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Installing Motherboards, CPUs, and Add-on Cards 220-1101: Objective 3.4: Given a scenario, install and configure motherboards, central processing units (CPUs), and add-on cards. Everything on a computer connects to the motherboard, where the CPU, the brains of a computer, resides. With so many different uses of computers, it follows that there are many different designs for how parts and devices attach to the motherboard to access the CPU. The A+ objectives cover the form factors that you will most likely encounter at some point as a technician. Motherboard Form Factors Form factor refers to the size, shape, and other specifications of a motherboard. These other specifications can include the location of the mounting holes, the type of power supply, the external ports, and so on. Computer chassis are designed to accommodate specific form factors, and knowing these common standard form factors is essential for an A+ technician:
ATX and mATX The Advanced Technology eXtended (ATX) family of motherboards has dominated desktop computer designs since the late 1990s. An ATX motherboard has the following characteristics: A rear port cluster for I/O ports Expansion slots that run parallel to the short side of the motherboard Left-side case opening (as viewed from the front of a tower PC)
The ATX family has two members; A Typical Late-Model ATX Motherboard mATX and ATX have matching mounting holes, and an mATX usually can be placed in an ATX case.
Table: ATX Motherboard Family Comparison
A Typical Late-Model microATX (mATX) Motherboard ITX Family The Information Technology eXtended (ITX) family of motherboards was originally developed by VIA Technologies in 2001 for use with its low-power x86 C3 processors. The original ITX motherboard form factor was quickly superseded by the smaller Mini-ITX form factor. Mini-ITX (mITX) measures 6.7×6.7 inches and has been adopted by many vendors for use with Advanced Micro Devices (AMD) and Intel processors. These processors can be socketed or soldered in place. Original designs featured a single PCI expansion slot, but most recent designs include a PCIe x1 or x16 expansion slot instead. A Mini-ITX motherboard can typically fit into a case made for ATX-family motherboards and uses a similar port cluster; however, Mini-ITX motherboards are used in small form factor PCs and in home theater applications.
The figure below shows a typical Mini-ITX motherboard optimized for home theater applications. It uses a low-power CPU soldered to the motherboard, a fanless passive heat sink, and SODIMM memory to reduce heat and allow for very quiet operation. It includes a miniPCIe slot (normally found in laptops) for use with a Wi-Fi card. Some Mini-ITX motherboards feature socketed processors and a PCIe x16 slot for high-performance 3D video, making them suitable for gaming. A Typical Mini-ITX (mITX) Motherboard Optimized for Home Theater Applications Comparing ATX, microATX, and Mini-ITX Motherboards This figure compares the general sizes and layouts of ATX, microATX (mATX), and Mini-ITX (mITX) motherboards. ATX, microATX, and Mini-ITX Motherboard Component Layouts Compared Motherboard Connector Types Motherboards use connectors to attach peripheral components to expand computing options. These are commonly known as expansion slots to provide support for additional input/output (I/O) devices and high-speed video/graphics cards. The most common expansion slots are PCI Express (also known as PCIe). Peripheral Component Interconnect (PCI) Slots A Peripheral Component Interconnect (PCI) slot (developed in 1992) mounts to the motherboard and is used for many types of add-on cards, including network, video, audio, I/O, and storage host adapters for SATA drives. Several types of PCI slots exist, but the one found in desktop computers is the 32-bit slot running at 33MHz (see Figure 3-48 in the next section). PCI slots are also available in 66MHz versions and in 64-bit versions. PCI Express Compared to PCI Slots Early PCI cards used 5V DC power, but virtually all 32-bit PCI cards in use for a number of years have used 3.3V DC power. Note that although PCI slots are mostly obsolete, they are still found on many motherboards for backward compatibility. PCIe (PCI Express) Slots Peripheral Component Interconnect Express (PCIe) slots began to replace both PCI and Accelerated Graphics Port (AGP) slots in system designs starting in 2005. PCIe slots are available in four “lane” configurations: x1 x4 x8 x16
Each x refers to an I/O lane. The most common versions include the x1, x4, and x16 designs.
Some motherboards have two or more slots that use the x16 connector; however, the additional slots might actually support only x4 or x8 transfer rates (see Figure). A Motherboard Built for Multi-GPU Gaming That Has Three PCIe x16 Physical Connectors but Only One That Actually Provides x16 Speeds PCI Express has evolved over the years to keep up with processing and data transfer needs for improvements in NICs, Wi-Fi, graphics, and storage. Each generation doubles the performance of the previous generation in bandwidth and frequency. PCIe speeds are represented in both bandwidth (gigabytes per second, expressed as GBps or GB/s) and gigatransfer (the theoretical speed per lane used on the card). For example, PCIe version 3.0 used 4 I/O lanes of 8GB to reach an aggregate bandwidth of 32GB/s. Table 3-14 compares the recent versions of PCIe. Table: Comparison of Recent PCIe Versions
NOTE GT stands for gigatransfers. In the tables throughout this guide, GT/s stands for gigatransfers per second, which differs from Gb/s, or gigabits per second. GT/s has to do with clocking embedded into the data of PCIe traffic. Using GT clarifies that some of the data being counted is “overhead” data used to make the transfer reliable. The nature of GTs is beyond the scope of the A+ exam. Note: miniPCI and miniPCIe are reduced-size versions of the PCI and PCIe standards. They are used in laptop computers. Power Connectors Most motherboards feature headers for the power supply to connect and to supply added power for the drives, fans, lights, and CPU. Other headers will be lower voltage for data. For more information, see the section “Power Supplies,” later in this guide. SATA The motherboard’s Serial Advanced Technology Attachment (SATA) connectors are adjacent to the CPU. SATA connectors replaced IDE connectors, which were ribbonlike cables that were slower and more cumbersome and that needed to be assigned priority to hard drives. The most important improvement was speed, with first-generation SATA cables transferring data up to 1.5Gb/s. As SSDs came to market, SATA specifications improved to 3Gb/s, to match the faster data capabilities of the solid-state drives. The latest SATA version transfers data at 6Gb/s and can be up to 1m (3 ft.) in length. Each generation of SATA cable had some differences in connectors, but the speed difference came from the controllers on the devices they connected to the motherboard and the capability of the motherboard controllers to handle the faster speeds. eSATA External SATA (eSATA) connectors meet SATA standards for data, but the connectors are different from the internal SATA connectors. The eSATA cables have more sheathing, to protect data from interference for up to 2m (6 ft.) in length. Headers The term headers on a motherboard refers to the pin headers that the connectors plug into. Some user manuals use the terms interchangeably. M.2 As noted earlier, an M.2 (pronounced “M-dot-2”) is an SSD that can mount directly onto the motherboard or an expansion card, giving the drive more direct access to the CPU for much faster reading than is possible with an SSD. Motherboards must be specifically designed to accept an M.2 SSD. Motherboard Compatibility When selecting a motherboard and installing or upgrading components on a motherboard, it is important to ensure that the components are compatible with the motherboard. The following sections discuss important aspects of motherboard compatibility that are covered on the CompTIA A+ exam. Processor Compatibility Intel and AMD, the two main manufacturers of desktop CPUs, use different form factors for attaching the processor to the motherboard. Differences in how the CPUs physically attach and how they work internally means one brand’s CPU is not compatible with the other brand’s motherboard. Because Intel and AMD use different socket types on their motherboards, CPUs from Intel will not fit an AMD form factor, and vice versa. Independent manufacturers of motherboards, such as ASUS and ASRock, make several different boards that support CPUs from both companies. Intel uses a Land Grid Array (LGA) form factor for CPUs. The pins that connect the CPU to the motherboard are mounted on the motherboard’s socket. Because of the grid protruding from the socket, careful handling of the motherboard is essential; damage to any pin can ruin the motherboard. AMD, on the other hand, uses a Pin Grid Array (PGA) form factor, in which the contact pins that insert into the socket are mounted to the CPU itself. Of course, careful handling of the CPU is important here as well. When an AMD chip is installed, the pins and the socket should be carefully aligned; then the CPU must be gently dropped into the socket without any force applied by hand. The CPU is locked into place using a zero insertion force (ZIF) lever that acts as a retention arm that holds the chip in place.
Figure below shows an AMD CPU with a PGA. An AMD CPU with PGA (Left) and an Intel CPU with LGA (Right) AMD and Intel CPUs are also fundamentally different from one generation to the next. The CPU form factor must match the socket form factor when building a PC or when changing out a motherboard or CPU. For example, Intel’s Core i7 CPU uses an LGA 1151, meaning that it has 1,151 pins. The newer Core i9 uses an LGA 2066, with 2,066 pins. Because of the pin difference, each CPU needs a different motherboard. Similar differences occur between AMD generations. CPUs have evolved over time, and each generation of CPU, whether Intel or AMD, can make different demands of a motherboard. For example, earlier CPUs could support 32-bit processing but not 64-bit processing. When 64-bit CPUs became available, they did not work on motherboards designed for 32 bit because those motherboards could not support the additional RAM capabilities and other features. Current CPUs have graphics features that were not available in the previous generation, and the chipsets might need to be enhanced as well. When upgrading a system, it is wise to start with the speed and features you want from a CPU and then shop for a motherboard that supports it. Checking with the manufacturer is the only way to know for sure whether a new version of CPU will work with the current motherboard’s chipset. Central Processing Unit (CPU) Socket Types The socket on a motherboard holds the central processing unit (CPU). The CPU takes in instructions from the software and runs calculations to process them into meaningful output for the application. (CPUs are discussed in more detail later in this section.) Intel and AMD are the most prolific chip makers, and they design chips to efficiently perform certain tasks. For example, gaming chips might have one architecture, and chips for mining crypto currency might use another; desktops and mobile devices also have their own variations of chip design. Although Intel and AMD processors share two common architectures—x86 (used for 32-bit processors and for 64-bit processors running in 32-bit mode) and x64 (an extension of x86 that enables larger files, larger memory sizes, and more complex programs)—these processor families differ in two important ways: - Different processor sockets - Differences in multicore processor designs (discussed later in this section) The sockets used by these two companies are both physically and logically different, so they are not interchangeable. One will not physically fit into the motherboard of the other, and since CPUs are designed for certain motherboards, they cannot work together even if they could physically connect. Intel Intel has used many processor sockets over the years. Note that the number of sockets has increased over time to accommodate more cores and improved architectures. Intel uses a connecting pattern called a Land Grid Array (LGA), which refers to the more than 1,000 connecting surfaces, or lands, that fit onto the Intel socket pins that wire into a motherboard. Common LGA models include the following: - LGA 775 - LGA 1155 - LGA 1156 - LGA 1366 - LGA 1150 - LGA 2011 - LGA 2066 Note: So many types of specialty CPUs exist (along with a maddening number of code names) that keeping it all straight is difficult. Before you buy any CPU from the vendor, be sure that what you are buying will work with what you have. For example, see the Automated Relational Knowledgebase, also known as the Intel ARK website (https://ark.intel.com). Land Grid Array Sockets The LGA design uses spring-loaded lands in the processor socket (see Figure 3-51) that connect to bumps on the backside of the processor. The number of lands in the processor socket is used for the numeric part of the socket name. For example, LGA 1150 has 1150 lands in the processor socket. An LGA 1155 Socket Prepared for Processor Installation The Front and Back Sides of an LGA Processor Before Installation Note: An excellent resource for information about currently available Intel processors and discontinued models is the Intel ARK website (https://ark.intel.com),mentioned earlier. To learn how to decode processor model number series, see “About Intel Processor Numbers,” at www.intel.com/content/www/us/en/processors/processor-numbers.xhtml. Mobile processors with similar model numbers can vary in features. Note: The latest Intel socket for desktop processors, Socket LGA2066, supports the Intel X-Series processors. To learn more about X-Series processors and matching chipsets, visit http://ark.intel.com. AMD AMD has used many processor sockets over the years, but the current desktop standard is the AM4. All these sockets use the micro Pin Grid Array (mPGA) design. Note: In the following sections, only processors with thermal design power (TDP) over 25 Watts are covered. Processors with 25 Watts or less TDP are typically used in laptops or all-in-one units rather than typical desktops. mPGA Sockets The micro Pin Grid Array (mPGA) design uses pins on the back side of the CPU to connect to pins in the processor socket. To hold the CPU in place, a zero insertion force (ZIF) socket mechanism is used. Open the arm and insert the processor; then close the arm to clamp the CPU pins in place. The heat sink clips to mounting lugs on two sides of the processor socket. All the mPGA sockets listed at the beginning of this section work in the same way.
The Figure shows Socket FM2, which uses mPGA. Figure 3-54 shows the back side of a processor designed for Socket FM2. Socket FM2 Before Processor Installation The Back Side of an AMD A10 5800K Processor Made for Socket FM2 The CPU series numbers contain codes and naming conventions for features or strengths of the chips, or they might indicate when a new generation of chip was developed. For example, features in an Intel i9 Core were developed later than an i7 Core, even though their production time overlapped. Each CPU can be compatible with chipsets on many compatible boards, so the manufacturer’s online database is invaluable. Table: Examples of Intel and AMD Desktop and Mobile Series CPUs
Servers Data center servers are specially designed for their main task of data retrieval and storage. Graphics and other tasks common to a desktop are not required of a server, but high performance and lower power consumption are. CPU manufacturers therefore create special server CPUs for these machines. The latest generation of servers has multisocket support, with Intel Xeon CPU and AMD Threadripper allowing two CPU sockets to work together. Newer models support up to eight sockets. Table: Server CPU Comparison
Having more than one CPU on a motherboard means having more physical sockets and more supporting design, which is not practical for desktop or even gaming machines. Mobile Laptops, tablets, and phones each have motherboard standards. CPUs generate heat, and mobile devices rarely include fans, so mobile CPUs are made to run on lower voltage and to sleep when not needed. The motherboards are much smaller than the AMD and Intel designs mentioned earlier. Table: Comparison of ITX Dimensions for Mobile Devices
Basic Input/Output System (BIOS)/Unified Extensible Firmware Interface (UEFI) Settings The Basic Input/Output System (BIOS) is an essential component of the motherboard. This boot firmware, also known as System BIOS or, on most recent systems, Unified Extensible Firmware Interface (UEFI), is the first code run by a computer when it is booted. It prepares the machine by testing it during bootup and paves the way for the operating system to start. It tests and initializes components such as the processor, RAM, video card, hard drives, optical drives, and USB drives. If any errors occur, the BIOS/UEFI reports them as part of the testing stage, known as the power-on self-test (POST). The BIOS/UEFI resides on a ROM chip and stores a setup program that you can access when the computer first boots up. From this program, it is possible to change settings in the BIOS and upgrade the BIOS as well. Note: From this point on in the guide, the term BIOS/UEFI refers to both traditional BIOS and UEFI firmware, except when they differ in function. BIOS/UEFI Configuration The system BIOS/UEFI has default settings provided by the system or motherboard maker, and these settings work fine for most people out of the box. However, as a system is built up with storage devices, memory modules, adapter cards, and other components, it is sometimes necessary to alter the default settings to get the best use of the devices. The changes to BIOS/UEFI are made using the BIOS/UEFI setup program and then saved to the CMOS (complementary metal-oxide semiconductor) chip on the motherboard. Note: macOS provides operating system menus for making changes to system devices instead of permitting direct access to the BIOS. Accessing the BIOS/UEFI Setup Program The BIOS/UEFI configuration program is stored in the BIOS/UEFI chip itself. Just press the key or key combination displayed onscreen (or described in the manual) when the system starts booting to access the BIOS/UEFI program menu. Although these keystrokes vary from system to system, the most popular keys on current systems include Escape (Esc), Delete (Del), F1, F2, and F10. Most recent systems display the key(s) necessary to start the BIOS/UEFI setup program at startup. If you do not know which key to press to start your computer’s BIOS/UEFI setup program, however, check the system or motherboard manual for the correct key(s). A Typical Splash Screen That Displays the Keystrokes Needed to Start the BIOS Setup Program Note: Because the settings you make in the BIOS/UEFI setup program are stored in the nonvolatile CMOS, the settings are often called CMOS settings or BIOS/ UEFI settings. The contents of CMOS are maintained by a battery. Warning: BIOS/UEFI configuration programs vary widely, but the screens used in the following sections are representative of the options available on typical recent systems; your system might have similar options but place the settings on different screens than those shown here. Laptops, corporate desktops, and tablets generally offer fewer options than those shown here. Be sure to consult the manual that came with your computer or motherboard before you change the settings you find here. Fiddling with the settings can improve performance, but it can also wreak havoc on an otherwise healthy device if settings are changed in error. UEFI and Traditional BIOS All desktop and laptop computers from 2014 on use a new type of firmware called the Unified Extensible Firmware Initiative (UEFI) to display a mouse-driven GUI or text-based menu for BIOS setup. macOS computers all use UEFI firmware. Compared to a traditional flash ROM BIOS, UEFI has the following advantages: - Support for hard drives of 2.2TB and higher capacity. These drives require use of the GUID Partition Table (GPT) to access full capacity. - Faster system startup (booting) and other optimizations. - Larger-size ROM chips used by UEFI to make room for additional features, better diagnostics, the capability to open a shell environment for easy flash updates, and the capability to save multiple BIOS configurations for reuse.
UEFI firmware offers similar settings to those used by a traditional BIOS (see Figure 3-56), along with additional options. Most desktop systems with UEFI firmware use a mouse-driven graphical interface. However, many laptops with UEFI firmware use a text-based interface similar to BIOS. A Computer That Uses a Traditional BIOS To learn more about UEFI, visit www.uefi.org. BIOS/UEFI Settings Overview The following sections review the typical setup process using various UEFI firmware versions on systems running Intel Core i3 3227U, Intel Core i5 i6600, AMD FX-8350, and AMD A10-5800K processors. Table below provides detailed information about the most important CMOS/BIOS settings. Use this table as a quick reference to the settings you need to make or verify in any system. The following sections provide examples of these and other settings. Table: Major CMOS/BIOS/UEFI Settings
As you can see in Table 3-18, you have many options to select from when configuring BIOS settings. Many BIOS firmware versions enable you to automatically configure your system with a choice of these options from the main menu: - BIOS defaults (also referred to as Original/Fail-Safe on some systems) - Setup defaults (also referred to as Optimal on some systems)
These options primarily deal with performance configuration settings in the BIOS firmware, such as memory timings and memory cache. The settings used by each BIOS setup option are customized by the motherboard or system manufacturer. Use BIOS defaults to troubleshoot the system because these settings are conservative in memory timings and other options. Normally, the setup defaults provide better performance. As you view the setup screens in this guide, you’ll see that these options are listed. Warning: If you use automatic setup after you make manual changes, all your manual changes will be overridden. Use the setup defaults and then make any other changes you want. With many recent systems, you can select optimal or setup defaults, save your changes, and then exit; the system will then work acceptably. However, to configure drive settings or USB settings, or to enable or disable ports, you also need to work with individual BIOS settings, such as the ones shown in the following sections. Tip: On typical systems, you set numerical settings, such as date and time, by scrolling through allowable values with keys such as + and – or Page Up/Page Down. However, to select settings with a limited range of options, such as to enable/disable or choose from a menu, press Enter or the right-arrow key on the keyboard and then choose the option you want from the available choices.
Boot Options: Settings and Boot Sequence Most computers include settings that control how the system boots and the sequence in which drives are checked for bootable operating system files. Depending on the system, these settings might be part of a larger menu, such as an Advanced Settings menu, a BIOS Features menu, or a separate Boot menu. Boot Sequence and Other Boot Settings in the UEFI/BIOS Features Menu A Typical Boot Menu Configured to Permit Booting from a CD/DVD or USB Flash Drive Before the Hard Drive Enabling Fast Boot skips memory and drive tests to enable faster startup. Enabling Boot Up NumLock turns on the keyboard’s NumLock option. The menus shown in Figures 3-57 and 3-58 are used to adjust the order in which drives are checked for bootable media. For faster booting, set the hard drive with system files as the first boot device. However, when you want to have the option to boot from an optical (CD/DVD/Blu-ray) disc or from a USB flash or hard drive for diagnostics or operating system installations, put those drives before SATA hard drives in the boot order. Note: Even when the first boot drive is set up as CD/DVD, some discs prompt the user to press a key to boot from the CD/DVD drive when a bootable disc is found. Otherwise, the system checks the next available device for boot files.
Firmware Updates Interestingly, a flash BIOS update is not available from BIOS manufacturers (Phoenix, Insyde, AMI, and Award/Phoenix). They do not sell BIOS updates because their basic products are modified by motherboard and system vendors. Following are the general steps to locate a flash BIOS update and install it:
Step 1. For major brands of computers, go to the vendor’s website and look for links to downloads or tech support. The BIOS updates are listed by system model and by version; avoid beta (prerelease) versions.
Tip: If your system is a generic system (that is, it came with a mainboard or motherboard manual and other component manuals instead of a full system manual), you need to contact the motherboard maker. You can also buy a replacement flash BIOS file from www.eSupport.com if you cannot get an updated BIOS code from your system or motherboard vendor. To determine the motherboard’s make and model, you can download and run Belarc Advisor (free for personal use) from www.belarc.com/free_download.xhtml.
See the following websites for additional help: - Wims BIOS page (www.wimsbios.com) - BIOSAgentPlus (www.biosagentplus.com) - AMI (American Megatrends International LLC, formerly American Megatrends Inc.): https://www.ami.com/ Step 2. Locate the correct BIOS update for your system or motherboard. For generic motherboards, the Wims BIOS page also has links to the motherboard vendors’ websites. Step 3. Determine the installation media needed to install the BIOS image. Many recent systems use a Windows-based installer, but some use a bootable CD or USB flash drive. Step 4. Be sure to download all the files needed to install the BIOS image. In most cases, a download contains the appropriate loader program and the BIOS image. For some motherboards, you might also need to download a separate loader program. If the website has instructions posted, print or save them for reference. Step 5. If you need to create bootable media, follow the vendor’s instructions to create the media and place the loader and BIOS image files on the media. Step 6. To install from bootable media, follow step 6a. To install from within Windows, follow step 6b. Step 6a. To install from bootable media, make sure the drive is the first item in the BIOS boot sequence. Insert or connect your media, and restart the system. If prompted, press a key to start the upgrade process. Some upgrades run automatically, others require you to choose the image from a menu, and still others require the actual filename of the BIOS. The BIOS update might also prompt you to save your current BIOS image.
Choose this option, if possible, so that you have a copy of your current BIOS, in case a problem arises. After the process starts, it takes approximately 3 minutes to rewrite the contents of the BIOS chip with the updated information. Step 6b. For installation from Windows, close all Windows programs before you start the update process. Navigate to the folder containing the BIOS update, and double-click it to start the update process. Follow the prompts onscreen to complete the process. It takes approximately 3 minutes to rewrite the contents of the BIOS chip with the updated information. Warning: While performing a flash upgrade, make sure you do not turn off the power to your PC and that you keep children or pets away from the computer, to prevent accidental shutdown. Wait for a message indicating that the BIOS update has been completed before you touch the computer. If the power goes out during the flash update, the BIOS chip could be rendered useless. Step 7. Remove the media and restart the system to use your new BIOS features. Reconfigure the BIOS settings, if necessary.
Recovering from a Failed BIOS Update If the primary system BIOS is damaged, keep in mind that some motherboard vendors offer dual BIOS chips on some products. The secondary BIOS performs the same functions as the primary BIOS so the system can continue to run. If you use the wrong Flash BIOS file to update your BIOS, or if the update process does not finish, your system cannot start. You might need to contact the system or motherboard maker for service or purchase a replacement BIOS chip. In some cases, the BIOS contains a “mini-BIOS” that can be reinstalled from a reserved part of the chip. Systems with this feature have a jumper on the motherboard called the flash recovery jumper. To use this feature, download the correct flash BIOS, make a bootable disc from it, and take it to the computer with the defective BIOS. Set the jumper to Recovery, insert the bootable media, and then rerun the setup process. Because the video will not work, you need to listen for beeps and watch for the drive light to run during this process. Turn off the computer, reset the jumper to Normal, and then restart the computer. If the update cannot be installed, your motherboard might have a jumper that write-protects the flash BIOS. Check the manual to see whether your system has this feature.
To update a BIOS on a system with a write-protected jumper, you must follow these steps: Step 1. Disable the write protection. Step 2. Perform the update. Step 3. Reenable the write protection to keep unauthorized people from changing the BIOS.
Security Features Security features of various types are scattered around the typical system BIOS/UEFI dialog boxes. Features and their locations vary by system and might include the following: - BIOS/UEFI password: BIOS Settings Password or Security dialog boxes - Power-on password: Configured through the Security dialog box - Chassis intrusion: Various locations - Boot sector protection: Advanced BIOS Features dialog box These features support drive encryption: - TPM (trusted platform module): Security dialog box - LoJack for laptops: An after-market product embedded in firmware or installed by the end user; not managed with BIOS dialog boxes - Secure Boot: Boot or other dialog boxes
Enable the BIOS password feature to permit access to BIOS setup dialog boxes only for those with the password. The power-on password option prevents anyone without the password from starting the system. Note that these options can be defeated by opening the system and clearing the CMOS memory. When intrusion detection/notification, also known as chassis intrusion, is enabled, the BIOS displays a warning on startup that the system has been opened. Boot sector protection, found primarily on older systems, protects the default system drive’s boot sector from being changed by viruses or other unwanted programs. Depending on the implementation, this option might need to be disabled before an operating system installation or upgrade. Windows editions that support the BitLocker full-disk encryption feature use the Trusted Platform Module (TPM) to protect the contents of any specified drive. Although many corporate laptops include a built-in TPM module, desktop computers and servers might include a connection for an optional TPM. LoJack for laptops (and other mobile devices) is a popular security feature embedded in the laptop BIOS of a number of systems, and it can be added to other systems. It consists of two components: a BIOS-resident component and the Computrace Agent, which is activated by LoJack when a computer is reported as stolen. To learn more about LoJack for laptops, tablets, and smartphones, see https://homeoffice.absolute.com. Secure Boot —blocks installation of other operating systems and also requires the user to access UEFI setup by restarting the computer in a special troubleshooting mode from within Windows 10/11. Secure Boot is enabled by default on systems shipped with Windows 10/11. Linux users or those who want more flexibility in accessing UEFI/BIOS (for example, technicians making changes in UEFI firmware) should disable Secure Boot.
Interface Configurations Typical desktop systems are loaded with onboard ports and features, and the menus shown in the figures below are typical of the BIOS menus used to enable, disable, and configure storage, audio, network, and USB ports. Fan Settings Shown in ASUS UEFI BIOS Utility’s Advanced Mode A UEFI Configuration Dialog Box for SATA Ports Configuring a USB Host Adapter for Battery Charging Configuring Onboard HD Audio Configuring an Onboard Network Adapter Fan Considerations Internal fan–related settings can be accessed in BIOS/UEFI. Adjustments can be made to CPU fans and, in some cases, other fans such as chassis fans. Fans that bypass the motherboard and connect directly into the power supply cannot be adjusted from BIOS/UEFI. Fans that connect directly into the motherboard, such as Pulse Width Modulation (PWM) fans, are typically adjustable from BIOS/UEFI settings. The fan settings options vary among motherboard vendors. Some BIOS/UEFI settings offer generic options, such as Quiet or Performance. Others offer options that can adjust the speed or percentage at which the fans are operating (see Figure 3-59). In some BIOS/UEFI models, settings can be implemented that adjust the fan speed based on the temperature inside the case.
SATA Configuration Use the SATA configuration options to enable or disable SATA and eSATA ports and to configure SATA host adapters to run in compatible (emulating PATA), native (AHCI), or RAID modes. AHCI supports native command queuing (NCQ) for faster performance and permits hot swapping of eSATA drives.
USB Host Adapters and Charging Support Most systems have separate settings for the USB (2.0) and USB 3.0/3.1/3.2 (a.k.a. SuperSpeed) controllers (on systems that have USB 3.0/3.1/3.2 ports). If you don’t enable USB 2.0 or USB 3.0/3.1/3.2 in your system BIOS, all your system’s USB ports will run at the next-lower speed. Some USB configuration utilities can also be used to enable a specified USB port to output at a higher amperage than normal, to enable faster charging of smartphones. Figure 3-61 illustrates a system with USB 3.0 support enabled and battery charging support being enabled.
Audio and Ethernet Ports Depending on the system, audio and Ethernet ports and other integrated ports might be configured using a common menu or separate menus.
In the figure below, the HD Azalia onboard audio is enabled; with a separate sound card installed, onboard audio should be disabled. SPDIF audio can be directed through the SPDIF digital audio port (default) or the HDMI AV port (optional) using this menu. In the figure below, the option Onboard LAN Option ROM is disabled on this system. Enable it when you want to boot from an operating system that is stored on a network drive.
CMOS Battery The system BIOS is responsible for configuring the ports and features controlled by the chipset, and the CMOS chip on the motherboard stores the settings. The CMOS battery provides power to maintain the contents of the CMOS chip. Battery life is several years, but a low CMOS battery can cause problems with drivers and sometimes booting. Because date and time settings are stored in CMOS, date and time errors can be a good indication that it is time to check or change the battery. A Typical CMOS Battery (CR2032) To clear CMOS on most systems, place a jumper block over two jumper pins. Note: Some systems feature a port cluster–mounted push button to clear the CMOS. If you need to clear the CMOS on a particular system, check the documentation for details.
Encryption Security has become the major concern in the design, manufacturing, and use of computers. Hackers find vulnerabilities in software to get into computers and compromise data. One method of mitigating the security threats is to have security processes separate from the software. To do this, specialized chips have been developed to manage hardware security away from the CPU. TPMs and HSMs are designed for different tasks, but both are important to desktop and laptop security.
Trusted Platform Module (TPM) As previously mentioned, a Trusted Platform Module (TPM) is a chip embedded into the motherboard of a desktop or laptop that enhances hardware security. The tasks it performs include generating and storing cryptographic keys to be used by the operating system, and managing authentication of the user booting up the system. Because they are processed separately from the CPU, there is little chance that the CPU can be hacked to acquire the keys. The TPM provides full disk encryption capabilities and protects disks during the boot process until the operating system can complete authentication. The TPM chip actually has its own small operating system for generating encryption keys separately from the CPU. TPMs are enabled in the BIOS/UEFI settings and are designed to be sure that the operating system is authentic and that the correct owner is booting the computer, but they do not manage other security keys needed by applications. Every certified Windows 11 system comes with a TPM chip. To view information about the TPM, open the Windows Defender Security application, select Device Security from the left menu, and then select Security Processor Details . Information About the TPM on Windows Hardware Security Module (HSM) A hardware security module (HSM) is not embedded into the motherboard. Instead, it is an added module or external device that can be added for storing security keys for general use. An important difference between TPMs and HSMs is that HSMs can store encryption data, but they do not generate the encryption keys as the TPMs do. Because HSMs are not embedded into the motherboard, they must access the CPU via USB, mounted in an extension slot, or, if being used by a network, via TCP/IP. Smartphones have similar chips on their motherboards for isolating security data, but they are beyond the scope of the current A+ exam.
CPU Architecture The architecture of a CPU refers to how it is designed to process data with its instruction set architecture (ISA). The ISA tells the CPU what to do and how to accomplish it. CPU manufacturers have adopted similar architectures, which are discussed in this section. x64/x86 Early CPUs from Intel were developed on the x86 architecture, which eventually allowed for 32-bit processing by the CPU. This means that 32 bits of data could be processed at one time and the CPU could address up to 4GB of RAM. This worked well for years, until more complex software needed more memory and faster processing. AMD developed the x64 CPU (also known as the x86-64), which greatly expanded the speed and memory access. The two most common architectures in use today by CPU manufacturers are the x86 and the x64. Table: Comparison of x86 and x64 CPUs
It is important to note that x64 CPUs can easily run the 32-bit x86 architecture, but the reverse is not true. To see if your Windows machine is running in 32- or 64-bit mode, search for “system information” to retrieve the data. Determining CPU Type Advanced RISC Machine (ARM) Reduced Instruction Set Computer (RISC) was designed to simplify CPUs from the x86 standards. Making the instruction set smaller for tasks enabled chip manufacturers to use fewer transistors, improving the efficiency of the computing process. Advanced RISC Machines (ARM) is a processor architecture that is based on RISC. ARM is the most widely used instruction set architecture. ARM processors are low cost, have minimal power consumption, and generate lower heat, making them ideal for devices such as smartphones, tablets, laptops, and other embedded systems. However, ARM processors are also utilized in desktops and servers. Additionally, ARM architecture is implemented on operating systems such as Windows, UNIX, Apple iOS, and Android.
CPU Cores: Single Core and Multicore A processing core is the part of the CPU that gets instructions from software and performs the calculations for output. Early computers had single-core processors to do all the work. As demands on CPUs grew, single-core processors could not keep up. Two or more physical processors in a system enable it to perform much faster when multitasking or running multithreaded applications. However, as mentioned earlier, systems with multiple processors are expensive to produce and are best used in server and enterprise computing. Multicore processors, which combine two or more processor cores into a single physical processor, provide virtually all the benefits of multiple physical processors, are lower in cost, and work with any operating system that supports traditional single-core processors. The operating system sees each core as a CPU.
Multithreading CPUs process the data from the operating systems, and delays in moving data in and out of the CPU meant there was downtime. Designers found an elegant way to “thread” additional work into the CPU while it was waiting for other operating instructions. This way, one physical core could behave like two logical cores. This process, known as hyperthreading, allowed much more processing than with one core alone. As CPUs developed and added cores, multithreading was designed as a method to allow multiple threads on each core. This works differently from hyperthreading: Multithreading breaks each core into logically smaller CPUs to handle more sets of operating instructions, resulting in higher CPU performance. The relationship between the motherboard socket, the cores in the CPU, and the logical processing from multithreading can be easily seen in the Task Manager in Windows, on the Performance tab.
Figure depicts a typical laptop or desktop CPU at work. Task Manager Depicting One Socket Holding a CPU with Four Cores Being Threaded, with the Capacity of Eight Logical Processors Virtualization Support Creating and managing a virtual version of a computer (or any device) is a rapidly growing sector in computing. Most current AMD and Intel processors feature virtualization support, also known as hardware-assisted virtualization. Virtualization support allows a physical CPU to be emulated as multiple individual CPUs that can be used in a virtualized operating system. This enables virtualized operating systems and applications to run faster and use fewer system resources. The benefits are too many to discuss here, but think of it as getting two or more computers running in software, but buying only one piece of hardware to run them. To check whether a Windows device has virtualization support enabled or disabled, navigate to the Task Manager; the Performance tab shows those details (see Figure 3-67). Virtualization is enabled and disabled through BIOS/UEFI firmware settings.
CPU Speeds Different components of the motherboard—such as the CPU, memory, chipset, expansion slots, storage interfaces, and I/O ports—connect with each other at different speeds. The term bus speeds refers to the speeds at which different buses in the motherboard connect to different components. On a motherboard, the bus is the path data takes between the internal components of the computer. Some of these speeds, such as the speed of I/O ports and expansion slots (USB, Thunderbolt, and SATA ports, as well as PCI and PCIe slots), are established by the design of the port or by the capabilities of the devices connected to them. However, depending on the motherboard, you might be able to fine-tune the bus speeds used by the processor, the chipset interconnect, and memory. These adjustments, where available, are typically performed through BIOS/UEFI firmware settings in menus such as Memory, Overclocking, and AI Tweaker.
The figure shows the dialog box for the CPU (processor) overclocking UEFI firmware for a system with an Intel i5 processor. The dialog box indicates the current CPU and memory multipliers that can be adjusted. CPU and Memory Speed Information on a System That Allows Speed Adjustment The figure illustrates the dialog box for memory overclock adjustments on the same system. To change the CPU speed, memory timing, or other adjustments, change the Auto setting and enter the desired values. On this system and others, you can select a CPU overclocking value; other settings are adjusted automatically as needed. Preparing to Overclock Memory Expansion Cards Most new CPUs come with integrated video, which is sufficient for everyday use. However, users of graphics applications and gamers will likely find a benefit in upgrading to an onboard graphics card that has dedicated memory space for graphics. The more integrated graphics processors are called upon, the more memory is used for processing and the more heat is generated by the CPU. A good video card has a separate processing chip and a cooling system that takes the load off the CPU and frees up space for the CPU to run more efficiently.
Installing Sound Cards A sound card converts the digital sound signal into an analog sound experience preferred by the human ear. For most users, the onboard sound card that is integrated into the motherboard is fine, but some users want high-fidelity sound for home theaters and music mixing. Purchasing an internal sound card that is more powerful and has more input/output options makes sense for professionals who work with sound. Installing a sound card is similar to installing a video card. Before installing a sound card, be sure to disable onboard audio with the system BIOS/UEFI setup program and uninstall any proprietary mixer or configuration apps used by onboard audio.
To install a sound card, follow these steps: Step 1. Shut down the computer and disconnect it from AC power. Step 2. Open the case to gain access to the PC’s expansion slots. Step 3. Select an empty PCIe or PCI expansion slot that is appropriate for the form factor of the sound card to be installed. Step 4. Remove the corresponding bracket from the back of the case. Step 5. Insert the card into the slot. A Typical PCIe Sound Card with 5:1 Surround Audio After Being Inserted into an Expansion Slot Step 6. Secure the card bracket into place, using the screw or locking mechanism you removed or released in step 4. Step 7. Connect any header cables as needed (refer to Figure 3-70). Step 8. Connect speakers, microphone, and line-in and line-out cables as needed to support your audio or home theater subsystem. Step 9. Close the system. Step 10. Reconnect AC power and restart the system. Step 11. Install the driver files provided with the sound card, or install updated versions provided by the vendor. Step 12. If they were not already installed in step 11, install the mixer and configuration utilities provided with the new sound card.
External USB Audio Sound Cards An external USB sound card can allow for higher-quality sound and multiple adapter input/output jacks. These sound cards really look more like USB-attached devices than cards, but they perform the same task as cards (for an example, see Sewelldirect.com). You can also add surround audio with a USB-based audio device. This is a good solution for laptops and for systems with limited or no expansion slots.
Installing a USB Audio Sound Card To install a USB audio device, follow these steps: Step 1. Turn off the computer. Step 2. Connect the USB audio device to the computer’s USB 2.0, USB 3.0, or USB4 port. Step 3. Turn on the computer and then turn on the device. The computer installs audio drivers automatically. Step 4. If needed, install additional or updated drivers downloaded from the vendor’s website or provided with the device.
Configuring a Sound Card with Windows To configure a sound card, onboard audio, or USB audio with Windows, follow these steps: Step 1. Type Sound Settings in the search box. Step 2. Select the Sounds icon in the Control Panel. Step 3. Select the Playback tab and adjust the settings. Step 4. Select the Recording tab and adjust the settings. Step 5. To specify sounds to play during Windows events (startup, shutdown, errors, and program events), use the Sounds tab. Step 6. Click Apply and then click OK to accept changes. If the sound card or onboard audio includes proprietary management or configuration programs, run them from the Start menu.
Configuring a Sound Card with macOS To configure a sound card, onboard audio, or USB audio with macOS, follow these steps: Step 1. Open the Apple menu. Step 2. Open System Preferences. Step 3. Select the Sound icon. Step 4. Select the Output tab. Step 5. Select the device to use for sound output. Step 6. Adjust the balance and volume, and then close the window.
Configuring a Sound Card with Linux To configure a sound card, onboard audio, or USB audio with Linux (Ubuntu 21.x), follow these steps: Step 1. Open System Settings. Step 2. Open Sound. Step 3. Under the Output section, select the device to use for sound output. Step 4. Adjust the balance and volume. Step 5. Select the speaker mode (stereo or surround options). Step 6. Click Test Sound to verify proper operation. Step 7. Close the window to save the changes.
Installing Video Cards The installation process for a video card includes three phases: Step 1. Configure the BIOS for the video card being installed. Step 2. Physically install the video card. Step 3. Install drivers for the video card.
The figure illustrates a typical high-performance video card that uses an AMD GPU. A PCIe x16 Video Card Designed for Multi-GPU (CrossFire) Support BIOS/UEFI Configuration for Video Cards Video cards interact differently, depending on the motherboard and BIOS/UEFI settings. When adding a card, you might need to enter BIOS/UEFI to disable the onboard video; some other systems allow both video systems to interact, for better efficiency.
These are the basic steps for BIOS/UEFO configuration for video cards: Step 1. Check and adjust the primary VGA BIOS setting (for the primary graphics adapter), as needed: Step 2. Choose PCIE or PCIE PCI if you use a PCIe video card. On some systems, the term NB PCIe Video Slot is used for PCIe. Step 3. Choose PCI or PCI PCIE if you use a PCI video card.
For onboard video (integrated graphics), see the manufacturer’s recommendation. (Onboard video can use PCI or PCI Express buses built into the motherboard.) On some recent systems, Auto is the default setting. If the installed video card and driver are not working well, but the screen is still visible, remove the card and use the Device Manager Driver Rollback feature to restore the previous driver.
Removing Drivers for an Old Video Card or Onboard Video Although all video cards created since the beginning of the 1990s are based on VGA, virtually all of them use unique chipsets that require special software drivers to control acceleration features (faster onscreen video), color depth, and resolution. Whenever you change video cards, you must thus change the video driver software as well. Otherwise, your operating system will drop into a low-resolution mode and might give you an error message because the driver does not match the video card. To delete an old video driver in Windows, open Control Panel Device Manager and delete the listing for the current video card. Right-click on a program and select Uninstall in Programs and Features; then uninstall the driver or configuration apps used by the current video card. It is not necessary to delete old drivers in macOS or Linux.
Removing the Old Video Card Follow these steps to remove an old video card (if present): Step 1. Shut down the computer and disconnect it from AC power. Step 2. Turn off the display. Step 3. Disconnect the data cable attached to the video card. Step 4. Open the case. Step 5. Disconnect any power cables running to the video card (see Figure 3-72). Removing the PCIe Power Cable from a Video Card Step 6. Remove SLI (NVIDIA) or CrossFire (AMD) cables connected to any card(s) you are removing. SLI and CrossFire Cables, which Should Be Removed Before Removing the Video Cards for Replacement Step 7. Remove the old video card(s) by removing the screw holding a card bracket in place and releasing the card-retention mechanism that holds video card in place. Repeat for each video card. Releasing the Card-Retention Mechanism Before Removing a PCIe x16 Video Card Note: Card-retention mechanisms vary widely among motherboards. In addition to the design shown in Figure 3-74, some use a lever that can be pushed to one side to release the lock; others use a knob that is pulled out to release the lock. To complete a CrossFire or SLI installation, use the configuration apps supplied with the video card drivers to enable CrossFire or SLI, and select specific 3D performance settings.
Video Card Physical Installation Follow these steps to install the new video card: Step 1. Insert the new video card into a PCIe x16 slot. If the motherboard has two or more PCIe x16 slots, use the slot closest to the port cluster for the primary (or only) card. Step 2. Lock the card into position with the card-retention mechanism and with the screw for the card bracket. Step 3. If the card uses power, connect the appropriate PCIe power connector to the card (refer to Figure 3-72). Step 4. If the card is running in multi-GPU mode and uses SLI or CrossFire, connect the appropriate bridge cable between the new card and a compatible existing (or new) card in the system Step 5. Reattach the data cable from the display to the new video card.
Driver Installation Driver installation takes place when the system is restarted: Step 1. Turn on the display. Step 2. Reconnect power to the system and turn on the computer. Step 3. Provide video drivers as requested; you might need to run an installer program for the drivers. If you are installing the card under Linux, check with the card vendor for downloadable Linux drivers for your distribution. Step 4. If the monitor is detected not as a Plug and Play monitor but as a default monitor, install a driver for the monitor. Note: A driver disc or thumb drive might have been packed with the monitor, or you might need to download a driver from the monitor vendor’s website. If you do not install a driver for a monitor identified as a default monitor, you will not be able to choose from the full range of resolutions and refresh rates the monitor actually supports.
Integrated Graphics Processing Unit (GPU) Integrating the GPU into the processor facilitates faster video processing, easier access to memory, and lower-cost systems. The Intel Core i3, i5, and i7 CPUs and the AMD A-series advanced processing units (APUs) are the first processors to have integrated GPUs. The newer series from AMD, Ryzen 5 and Ryzen 7, and Intel i9 continue to improve on GPU processing.
Intel uses three different names to refer to its processor-integrated graphics: - HD Graphics refers to base-level 3D graphics in any given processor family. Specific features vary by processor family. - Intel UHD Graphics for 12th generation, formerly code-named Alder Lake, was released in 2021. - Intel Iris Xe Graphics, formerly code-named Alder Lake, was released in 2022. Several families of CPUs exist; you can find information about their GPUs at www.intel.com. The GPU-Z reporting app from TechPowerUp (www.techpowerup.com) can be used to display information about discrete or integrated GPUs.
This figure displays information about the HD Graphics 4000 GPU built into an Intel Core i3-2770U processor and the Radeon HD 6520G built into an AMD A6-3420M processor. GPU-Z Reports on Intel and AMD Processors with Integrated GPUs AMD, which also manufactures Radeon GPUs for video cards, integrates Radeon GPU features into its line of APUs, which integrate the CPU and GPU: - APUs in the Llano and Trinity series use Radeon HD 6xxxD, 7xxxD, and 8xxxD graphics using stream processor technology for 3D graphics. These support OpenGL 4.1 or better and OpenCL 1.1 or better. - Radeon R7 graphics in the 7000 series use Compute Cores, which permit both CPU and GPU cores to access the same memory. These support OpenGL 4.3 and OpenCL 1.2. - Radeon R5 graphics in the 7000 series feature fewer Compute Cores and run more slowly than R7, but are otherwise similar.
For more information about APU specifications, see www.amd.com. Although the fastest CPU-integrated graphics are suitable for casual gaming as well as general office use, high-performance graphics cards are still recommended for 3D gaming. If a high-performance card is installed, the GPU must be disabled in the BIOS/UEFI.
Video Capture Cards Although many TV tuner cards and USB devices are designed to work with analog video sources (S-Video or composite), they are not designed to work with HD video or high-resolution computer or video game sources. A true video capture card is equipped to receive HDTV or higher-quality signs via HDMI, DVI, or Component. Video capture cards have built-in hardware support for MPEG-4 recording and can be used to capture video for training, game recording, YouTube, or broadcast purposes. Some video capture devices connect to a USB port. To install a video capture card, follow these steps: Step 1. Turn off the computer, unplug it, and remove the case cover. Step 2. Locate an available PCIe expansion slot. Step 3. Remove the slot cover and insert the card into the slot. Secure the card in the slot. Step 4. Connect the appropriate cable between the video source (computer, video game, and so on) and the video capture card. Step 5. Close the system, reattach AC power, restart the computer, and provide the driver media when requested by the system. Step 6. Start the capture utility, and capture video or still images from the video source. Installing Network Cards Although most computers include a 10/100/1000 Ethernet port or a Wireless Ethernet (Wi-Fi) adapter, you sometimes need to install a network card (network interface card [NIC]) into a computer that you want to add to a network. To install a Plug and Play (PnP) network card, follow these steps: Step 1. Shut down the computer, disconnect it from AC power, and remove the case cover. Step 2. Locate an available expansion slot that matches the network card’s design. (Most use PCIe, but some servers and workstations might use PCI-X and some older desktop systems might use PCI.) Step 3. Remove the slot cover and insert the card into the slot. Secure the card in the slot. Step 4. Reconnect power to the system, restart the system, and provide drivers when requested by the system. Step 5. If you are prompted to install network drivers and clients, insert the operating system disc. Step 6. Connect the network cable to the card. Step 7. Test for connectivity (check LED lights, use a command such as ping, and so on), and then close the computer case.
If no slots are available, or if you need to add (or upgrade) network connectivity on a laptop, use a USB-to-Ethernet or USB-to-wireless adapter. Although USB network adapters are also PnP devices, you might need to install the drivers provided with the USB network adapter before you attach the adapter to your computer. After the driver software is installed, the device is recognized as soon as you plug it into a working USB port. Note: If you are using a wireless USB adapter, you can improve signal strength by using an extension cable between the adapter and the USB port on the computer. Using an extension cable enables you to move the adapter as needed to pick up a stronger signal. Most USB network adapters are bus powered. For best results, they should be attached to a USB port built into your computer or to a self-powered hub. Most recent adapters support USB 3.1 Gen 2 (10Gb/s), which provides support for 100BASE-TX (Fast Ethernet, 100Mb/s) and 1000BASE-T (Gigabit Ethernet, 1000Mb/s) signal speeds. A USB 2.0 port (480Mb/s) is adequate for Fast Ethernet but does not run fast enough for Gigabit Ethernet. USB4 offers two versions with differing speeds of 20Gb/s and 40Gb/s. Cooling Mechanisms A CPU is one of the most expensive components in any computer, and keeping it cool is important. The basic requirements for proper CPU cooling include the use of an appropriate active heat sink (which includes a fan) and the application of an appropriate thermal material (grease, paste, or a preapplied thermal or phase-change compound). Advanced systems sometimes use liquid cooling instead. Fans A traditional active heat sink includes a cooling fan that rests on top of the heat sink and pulls air past the heat sink in a vertical direction. However, many aftermarket heat sinks use other designs. Stock (Original Equipment) Active Heat Sinks Made for AMD (Left) and Intel (Right) Processors Typical Third-Party Active and Passive Heat Sinks Fanless/Passive Heat Sinks A passive heat sink does not include a fan, but it has more fins than an active heat sink, to help dissipate heat. One typical use for fanless heat sinks is on low-power processors that are soldered in place on Mini-ITX or similar small form factor motherboard designs, such as the one shown in Figure below. A Low-Power Mini-ITX Motherboard Designed for Home Theater and Media Streaming Heat Sink Every processor requires a heat sink. A heat sink is a finned metal device that radiates heat away from the processor. In almost all cases, an active heat sink (a heat sink with a fan) is required for adequate cooling. However, if a system case (chassis) is specially designed to move air directly over the processor, then a fanless passive heat sink can be used instead. Aluminum has been the most common material used for heat sinks, but copper has better thermal transfer properties. Many designs therefore mix copper and aluminum components. (Figures below show two examples of heat sinks.)
Bottom View of OEM (Original Equipment Manufacturer) Active Heat Sinks Made for Intel and AMD Processors Phase-Change Material/Thermal Paste Before installing a heat sink bundled with a processor, remove the protective cover over the preapplied thermal material (also known as phase-change material) on the heat sink. When the heat sink is installed on the processor, this material helps ensure good contact between the CPU and the heat sink, to maximize heat transfer away from the CPU.
Tip: When you remove a heat sink, keep in mind that the thermal compound acts as an adhesive. Make sure you have loosened the locking mechanism before you remove the heat sink. You might need to exert some force to remove it from the processor. If you need to remove and reapply a heat sink, be sure to remove all residue from both the processor and the heat sink using isopropyl alcohol, and apply new thermal paste or a thermal pad to the top of the CPU. Thermal paste is applied with a syringe; it is important to use the correct amount, about the size of a pea. Applying too little or too much thermal paste will lead to less than effective results; applying too much involves the risk of the material spilling out onto the motherboard. Thermal pads can be an easier, less messy option because the material can be cut to size.
Liquid-Based Cooling Liquid-based cooling systems for processors, motherboard chipsets, and GPUs are available. Some are integrated into a custom case, whereas others can be retrofitted into an existing system that has openings for cooling fans. A liquid cooling system involves attaching a liquid cooling unit instead of an active heat sink to the processor and other supported components. A pump moves the liquid (which might be water or a special solution, depending on the cooling system) through the computer to a heat exchanger, which uses a fan to cool the warm liquid before it is sent back to the processor. Liquid cooling systems are designed primarily for high-performance systems, especially overclocked systems. It is essential that only approved cooling liquids and hoses be used in these systems (check with cooling system vendors for details); unauthorized liquids or hoses could leak and corrode system components.
Figure illustrates a typical liquid cooling system, compared to a typical Intel OEM heat sink. A Typical Liquid Cooling System and Active Heat Sink
220-1101: Objective 3.5: Given a scenario, install or replace the appropriate power supply. Power supplies vary widely in features and ratings. When building a custom configuration or updating a system to perform a specific task, the power supply is a critical factor in the success of that system.
The power supply is so named because it converts power from high-voltage alternating current (AC) to low-voltage direct current (DC). Many wire coils and other components inside the power supply do the work, and during the conversion process, a great deal of heat is produced. Most power supplies include one or two fans to dissipate the heat created by the operation of the power supply; however, a few power supplies designed for silent operation use passive heat sink technology instead of fans. On power supplies that include fans, fans also help to cool the rest of the computer.
Figure shows a typical desktop computer’s power supply. A Typical ATX Power Supply Power Supply Ratings Power supply capacity is rated in Watts; and the more Watts a power supply provides, the more devices it can safely power. You can use the label attached to a power supply to determine its wattage rating and see important safety reminders. Typical Power Supply Labels A power supply with two separate +12V rails is a dual-rail design. Some high-performance power supplies feature more than two +12V outputs, such as the 650-Watt model shown in the Figure. Another term for two or more +12V outputs is split rail. Note: Power supplies with two or more separate +12V power sources are common today for providing adequate power for CPUs (which use voltage regulators on the motherboard or in the CPU itself to reduce +12V power to the power level needed) and other devices, such as PCIe video cards, fans, and drives. Add together the values of the +12V rails to get the total +12V output in amps. Note: Wattage vs. Amperage The power supply label shown at the top of Figure below is rated at 650 Watts, whereas the power supply label shown at the bottom of the figure is rated at 700 Watts. Take a closer look at the amperage ratings, though, and it becomes clear that the 650-Watt power supply provides much more of the +12V power needed by processors and motors. The 650-Watt power supply provides a total of 80A on the +12V lines (20A each on four +12V lines). The 700-Watt power supply provides only 52A on its +12V line. The 700-Watt power supply provides no information about the temperature or load factor at which its rating is calculated, whereas the 650-Watt power supply indicates that its calculations are made at 50° Celsius (about 122° Fahrenheit) at full load. Despite the rating difference, the 650-Watt power supply shown in Figure 3-82 clearly provides more useful power than the 700-Watt power supply in the same figure.
Input 115V vs. 220V Multivoltage Power Supplies Most power supplies are designed to handle two different voltage ranges: - 115–120V/60Hz - 220–240V/50Hz Power supplies that support these ranges are known as dual-voltage power supplies. Standard North American power is now 115–120V/60Hz-cycle AC. (The previous standard was 110V and is still covered in the A+ exam.) The power used in European and Asian countries is typically 230–240V/50Hz AC (previously 220V). How can you tell whether a power supply meets minimum safety standards? Look for the appropriate safety certification mark for your country or locale. For example, in the United States and Canada, the backward UR logo indicates that the power supply has the UL and UL Canada safety certifications as a component. (The familiar circled UL logo is used for finished products only.) Both power supplies shown in Figure below meet the safety standards for the U.S. and other nations. Note: The CompTIA A+ exam covers 110–120 VAC vs. 220–240 VAC. Warning: Power supplies that do not bear the UL or other certification marks should not be used because their safety is unknown. Typically, power supplies in recent tower case (upright case) machines use 500-Watt or larger power supplies, reflecting the greater number of drives and cards that can be installed in these computers. Power supplies used in smaller desktop computers have typical ratings of around 220 to 300 Watts. The power supply rating is found on the top or side of the power supply, along with safety rating information and amperage levels produced by the power supply’s different DC outputs. Some older power supplies have a slider switch with two markings: 115 (for North American 110–120V/60HzAC) and 230 (for European and Asian 220–240V/50Hz AC).
Figure shows a slider switch set for correct North American voltage. If a power supply is set to the wrong input voltage, the system will not work. Setting a power supply for 230V with 110–120V current is harmless; however, feeding 220–240V into a power supply set for 115V will destroy the power supply and possibly other onboard hardware. An Older Power Supply’s Sliding Voltage Switch Set for Correct North American Voltage (115V) Note: Most recent power supplies for desktop and laptop computers can automatically determine the correct voltage level and cycle rate. These are referred to as autoswitching power supplies, and they lack the voltage/cycle selection switch shown in Figure 3-83. The on/off switch shown in Figure 3-83 controls the flow of current into the power supply. It is not the system power switch, which is located on the front or top of desktop systems and is connected to the motherboard. When you press the system power switch, the motherboard signals the power supply to provide power. Warning: Unless the power supply is disconnected from AC current or is turned off, a small amount of power can still be flowing through the system even when it is not running. Do not install or remove components or perform other types of service to the inside of a PC unless you disconnect the AC power cord or turn off the power supply. Wait a few seconds afterward to ensure that the power is completely off. A desktop motherboard might have indicator lights that turn off when the power has completely drained from the system.
20-Pin-to-24-Pin Motherboard Adapter When shopping for a power supply, make sure it can connect to your motherboard. Almost all power supplies sold today have a 24-pin connector, but you could encounter a legacy 20-pin connector used by older motherboards in the ATX family. The 24-pin is used by recent ATX/microATX/Mini-ITX motherboards requiring the ATX12V 2.2 power supply standard. Most motherboards use power supplies that feature several additional connectors to supply added power, as follows: - Some high-wattage power supplies with 20-pin connectors might also include a 20-pin-to-24-pin adapter. Some 24-pin power supplies include a split connector to support either 24-pin or 20-pin motherboard power connectors. 20-Pin ATX and 24-Pin ATX Power Connectors, Compared to 4-Pin ATX12V and 6-Wire AUX Power Connectors - The four-wire square ATX12V connector provides additional 12V power to the motherboard. This connector is sometimes referred to as a P4 or Pentium 4 connector. - Most recent power supplies use the 4/8 pin +12V (EPS12V) connector (see Figure 3-84) instead of the ATX12V power connector. The EPS12V lead is split into two four-wire square connectors to be compatible with motherboards that use either ATX12V or EPS12V power leads. - Some very old motherboards use a six-wire AUX connector to provide additional power.
Figure shows both sides of a convertible 24-pin/20-pin ATX power supply connector. Both Sides of a 24-Pin ATX Power Supply Cable (Also Compatible with 20-Pin Motherboards) The power supply also powers various peripherals: - Hard disks and CD/DVD/BD optical drives - Case fans that do not plug into the motherboard and that use a four-pin Molex power connector - An L-shape, 15-pin thinline power connector for Serial ATA (SATA) hard disks - A PCI Express six-pin or eight-pin power cable (PCIe 6/8-pin) for high-performance PCI Express x16 video cards that require additional 12V power
Figure illustrates these power connectors and the EPS12V motherboard power connector. Power Supply Connectors for Peripherals and Modern Motherboards Output 3.3V vs. 5V vs. 12V Because different peripherals have varying voltage requirements, three different voltages are delivered to the motherboard from the power supply. Different connector types carry different voltages. Table 3-20 lists the power levels carried by each connector type. Table: Power Levels for Different Connector Types
If your power supply does not have enough connectors, you can add Y-splitters to divide one power lead into two, but these splitters can short out and also reduce the efficiency of the power supply. You can also convert a standard Molex connector into a SATA connector with the appropriate adapter.
Standard power supply wires are color-coded thus: - Red: +5V - Yellow: +12V - Orange: +3.3V - Black: Ground (earth) - Purple: +5V (standby) - Green: PS-On - Gray: Power good - White: No connection (24-pin); –5V (20-pin) - Blue: –12V
Redundant Power Supply Redundancy in a computer system or in network design means that a duplicate device is (or devices are) in place to keep things operational in case of failure. A power supply failure for even a second or two can be a disaster for a high-end computer or server. For systems requiring highly reliable uptime, a redundant power supply is an appropriate investment. Redundant power supplies are much more likely to be found in enterprise data centers than in personal computers or workstations. In most cases, a redundant power supply has two power supplies, including power cables, built into the case. If there are two power units, each of the units carries half the workload during normal operations. If one supply fails, however, the other power supply has enough power to take over operations and keep the system up until the failed supply can be replaced. Replacing the failed component can happen while the machine remains online if the power supply is hot swappable. A technician can unplug and remove the failed unit and replace it with a good one, and the units then return to sharing the work. The users of the computers will be unaware of the downtime. The idea of redundancy is to eliminate a single point of failure in the system. As an added precaution, some data centers even design separate electrical circuits for the redundant supplies. Note: A redundant power supply differs from an uninterruptible power supply (UPS), which is a separate device that sits outside the computer and provides temporary battery-powered backup if the building experiences a general power failure.
Modular Power Supply Some power supplies use modular connections so that you can customize the power supply connections needed for your hardware. An advantage of a modular power supply is that the cables can detach from the power supply, and cable management is much easier. A Modular Power Supply with Cables You Can Attach to Customize Support for Your System’s Needs If your wattage calculations or your tests agree that it is time to replace a power supply, make sure the replacement meets the following criteria: - Has the same power supply connectors and the same pinout as the original - Has the same form factor (shape, size, and switch location) as the original - Has the same or higher wattage rating as the original (a higher wattage rating is highly desirable) - Supports any special features required by your CPU, video card, and motherboard, such as SLI support (support for PCIe connectors to power two or more high-performance PCIe video cards), high levels of +12V power (ATX12V v2.2 4-pin or EPS12V 8-pin power connectors), and so on
Tip: To ensure form factor connector compatibility, consider removing the old power supply and taking it with you if you plan to buy a replacement at retail. If you are buying a replacement online, measure the dimensions of your existing power supply to ensure that a new one will fit properly in the system. So-called EPX power supplies are longer than ATX power supplies and do not fit into smaller cases. When replacing a power supply, make sure the new one is robust enough to handle any extra work from upgrades in the past or planned upgrades in the future. Power supplies are best in the middle of their wattage range; a PC that is underpowered can have many problems that are difficult to diagnose. The power supply is no place to scrimp on budget. To determine the wattage rating needed for a replacement power supply, add up the wattage ratings for everything connected to your computer that uses the power supply, including the motherboard, processor, memory cards, drives, and bus-powered USB devices. Include any external devices that are used occasionally. If the total wattage used exceeds 70 percent of the wattage rating of your power supply, you should upgrade to a larger power supply. Check the vendor spec sheets for wattage ratings. If you have amperage ratings instead of wattage ratings, multiply the amperage by the volts to determine the wattage, and then start adding. If a device uses two or three different voltage levels, be sure to carry out this calculation for each voltage level; then add up the figures to determine the wattage requirement for the device. Review Figure 3-82 and the “Wattage vs. Amperage” sidebar, earlier in this guide, for a reminder of the importance of +12V amperage. This table provides calculations for typical compact desktop and high-performance desktop systems, based on the eXtreme Outer Vision online calculator at https://outervision.com. Table: Calculating Power Supply Requirements
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