Choosing a gaming motherboard is a hugely important part of building a PC.
What does a motherboard do? It’s the circuit board that connects all of your hardware to your processor, distributes electricity from your power supply, and defines the types of storage devices, memory modules, and graphics cards (among other expansion cards) that can connect to your PC.
Below, we’ll dive into motherboard anatomy and give you all the information you need to learn how to choose a motherboard for your build.
Motherboard Anatomy
A motherboard is a PC’s primary circuit board. Though motherboard aesthetics change over time, their basic design makes it easy to connect new expansion cards, hard drives, and memory modules, as well as replace old ones.
Let’s walk through some of the terms you’ll encounter when comparing motherboards.
Processor Socket
Motherboards usually contain at least one processor socket, enabling your CPU (the PC’s mechanical “brain”) to communicate with other critical components. These include memory (RAM), storage, and other devices installed in expansion slots — both internal devices like GPUs and external devices like peripherals.
(Not all motherboards have a socket, though: in systems with less space, like mini PCs and most laptops, the CPU is soldered into the motherboard.)
When selecting a motherboard, check your CPU’s documentation to ensure the board is compatible with your CPU. Sockets vary in order to support different products based on generation, performance, and other factors by changing the pin array. (The name of the socket comes from the pin array: for example, the LGA 1151 socket, compatible with 9th Gen CPUs, has 1,151 pins.)
Modern motherboards connect CPUs directly to RAM, from which it fetches instructions from different programs, as well as to some expansion slots that can hold performance-critical components such as GPUs and storage drives. The memory controller lives on the CPU itself, but numerous other devices communicate with the CPU through the chipset, which controls many expansion slots, SATA connections, USB ports, and sound and network functions.
Chipset
The chipset is a silicon backbone integrated into the motherboard that works with specific CPU generations. It relays communications between the CPU and the many connected storage and expansion devices.
While the CPU connects directly to RAM (via its built-in memory controller) and to a limited number of PCIe* lanes (expansion slots), the chipset acts as a hub that controls the other buses on the motherboard: additional PCIe lanes, storage devices, external ports like USB slots, and many peripherals.
Higher-end chipsets can feature more PCIe slots and USB ports than standard models, as well as newer hardware configurations and different allocations of PCIe slots (with more linked directly to the CPU).
Choosing a Chipset
Modern chipsets consolidate many features that were once discrete components connected to motherboards. Onboard audio, Wi-Fi, Bluetooth®3 technology, and even cryptographic firmware are now integrated into Intel chipsets.
High-end chipsets like Z390 can offer many benefits, including overclocking support, and higher bus speeds. But Intel chipsets also provide further improvements.
Here’s a quick breakdown of the differences between Intel’s chipset series:
Z-Series
- Overclocking support for CPUs with “K” designation
- Maximum of 24 PCIe lanes
- Up to six USB 3.1 Gen 2 ports
H-Series
- No overclocking support
- Maximum of 20 PCIe lanes
- Up to four USB 3.1 Gen 2 ports
B-Series
- No overclocking support
- Maximum of 20 PCIe lanes
- USB 3.0 ports only
These different options enable entry at a variety of price points, while still taking advantage of the benefits of the 300-series chipset.
Expansion Slots
PCIe
Peripheral Component Interconnect Express (PCIe) is a high-speed serial expansion bus integrated into either your CPU, motherboard’s chipset, or both. This allows the installation of devices like graphics cards, solid-state drives, network adapters, RAID controller cards, capture cards, and many other expansion cards into the PCIe slots of a motherboard. The integrated peripherals featured on many motherboards also connect via PCIe.
Each PCIe link contains a specified number of data lanes, listed as ×1, ×4, ×8, or ×16 (often pronounced “by one,” “by four,” etc.). Each lane consists of two pairs of wires: one transmits data and the other receives data.
With current-generation PCIe implementations, a PCIe ×1 link has one data lane with a transfer rate of one bit per cycle. A PCIe×16 lane, typically the longest slot on your motherboard (and also the one used most often for a graphics card), has 16 data lanes capable of transferring up to 16 bits per cycle. However, future iterations of PCIe will allow doubling the data rate per clock cycle.
Each revision of PCIe has roughly doubled the bandwidth of the previous generation, and that means better performance for PCIe devices. A PCIe 2.0 ×16 link has a theoretical, bidirectional peak bandwidth of 16 GB/s; a PCIe 3.0 ×16 link has a peak of 32 GB/s. When comparing PCIe 3.0 lanes, the ×4 link commonly used by many solid-state drives has a peak theoretical bandwidth of 8 GB/s, whereas the ×16 link that GPUs leverage offers four times as much.
Another feature of PCIe is the option to use slots with more lanes as a substitute for slots with fewer lanes. For example, a ×4 expansion card can be inserted into a ×16 slot and work normally. However, its throughput will be the same as if it was in a ×4 slot — the 12 additional lanes simply go unused.
Some motherboards have M.2 and PCIe slots that could use more PCIe lanes than are actually available on the platform. For example, some motherboards may have seven PCIe x16 slots, which could theoretically use 112 lanes, but the processor and chipset may feature only 48 lanes.
If all lanes are in use, PCIe slots will often switch to a lower bandwidth configuration. For example, if a pair of GPUs are installed in two ×16 PCIe slots, the links may run at ×8 rather than ×16 (modern GPUs are unlikely to be bottlenecked by a PCIe 3.0 ×8 connection). Some premium motherboards may use PCIe switches that fan out the physical lanes, however, so the slot lane configurations can remain unchanged.
Enthusiast motherboards, such as the Z-series, provide more PCIe lanes and greater flexibility for PC builders.
M.2 and U.2
M.2 is a compact form factor that fits small expansion devices (16-110mm long), including NVMe (non-volatile memory express) solid-state drives, Wi-Fi cards, and other devices.
M.2 devices have different “keys” (the arrangement of gold connections on the end) that determine compatibility with the socket on the motherboard. Though they can use many different interfaces, the most common M.2 cards use four PCIe low-latency data lanes or the older SATA bus.
Because M.2 cards are relatively small, they provide an easy way to expand storage capacity or system capability in a smaller system. They plug directly into the motherboard, thereby eliminating the cables necessary with traditional SATA-based devices.
U.2 connectors are an alternative interface that connects to 2.5” SSDs that use cabled PCIe connections. U.2 storage drives are frequently used in professional settings such as data centers and servers, though less frequently in consumer builds.
U.2 and M.2 both use the same number of PCIe lanes and are capable of comparable speeds, though U.2 supports hot swapping (meaning the drive can be removed while the system using it remains on) and can support more power configurations than M.2.
SATA
SATA (Serial ATA) is an older computer bus less commonly used today to connect to 2.5" or 3.5" hard drives, solid-state drives, and optical drives that play DVDs and Blu-ray.
Though slower than PCIe, the common SATA 3.0 interface supports data transfer speeds up to 6Gbit/s. The newer SATA Express (or SATAe) format uses two PCIe lanes to reach speeds up to 16Gbit/s. It’s not to be confused with External SATA (eSATA), an external port that allows easy connection of (compatible) portable hard drives.
RAM
Motherboards also have slots for RAM modules: sticks of volatile memory that temporarily store data for fast retrieval. Multiple sticks of high-speed RAM can help PCs handle simultaneous programs without slowdown.
Full-size motherboards (like the ATX form factor) typically have four slots, while size-constrained boards like mITX usually use two. However, HEDT motherboards can have up to eight.
Recent motherboards support dual-channel memory architecture, meaning there are two independent channels transferring data between the CPU’s memory controller and a stick of DIMM (dual in-line memory modules) RAM. As long as sticks of RAM are installed in pairs with matching frequencies, this leads to speedier data transfer and better performance in some applications.
Form Factor
Your motherboard’s form factor determines the size of case you need, the number of expansion slots you’ll have to work with, and many facets of the motherboard’s layout and cooling. In general, larger form factors give builders more DIMM, full-size PCIe, and M.2 slots to work with.
To make things easier for both consumers and manufacturers, desktop motherboard dimensions are highly standardized. Laptop motherboard form factors, on the other hand, often vary by manufacturer due to the unique size constraints. This can also be true for highly specialized pre-built desktops.
Common desktop motherboard form factors are:
- ATX (12” × 9.6”): The current standard for full-size motherboards. A standard consumer ATX motherboard usually features seven expansion slots, spaced 0.7” apart, and four DIMM (memory) slots.
- Extended ATX or eATX (12” x 13”): A larger variant of the ATX form factor designed for enthusiast and professional use, these boards have additional real estate for more flexible hardware configurations.
- Micro ATX (9.6” × 9.6”): A more compact variant of ATX featuring two full-size (×16) expansion slots and four DIMM slots. Fits into mini-towers, but remains compatible with the mounting holes in larger ATX cases.
- Mini-ITX (6.7” × 6.7”): Small form factor designed for use in compact computers without fan cooling. Provides one full-size PCIe slot and typically two DIMM slots. Mounting holes are again compatible with ATX cases.
What You Need to Know About BIOS
The first thing you see when your computer starts up is the BIOS, or Basic Input/Output System. This is the firmware that loads before your operating system boots up, and it’s responsible for starting up and testing all connected hardware.
Though often referred to as the BIOS by users and motherboard labels alike, the firmware on modern motherboards is typically UEFI (Unified Extensible Firmware Interface). This more flexible environment boasts many user-friendly improvements, such as support for larger storage partitions, speedier boot-up, and a modern GUI (graphical user interface).
Motherboard manufacturers often add UEFI utilities that streamline the process of overclocking the PC’s CPU or memory and provide helpful presets. They may also feature a stylized appearance, add logging and screenshot features, simplify processes like booting from another drive, and display monitor memory, temperature, and fan speeds.
UEFI also supports older features of the BIOS. Users can boot into Legacy mode (also known as CSM, or Compatibility Support Module) to access the classic BIOS, which may solve compatibility issues with older operating programs or utilities. However, when users boot in Legacy mode, they obviously lose the modern benefits of UEFI, such as support for partitions over 2TB. (Note: always backup important data before switching boot modes).
Internal Connectors
To power up every part of your motherboard, cables from the power supply and case must be plugged into connectors and headers (exposed pins) on the motherboard. Consult the visual reference in your manual, as well as the small text silkscreened onto your motherboard itself (such as CPU_FAN), to match each cable to the right connector.
Power and Data Connectors
- 24-pin power connector
- 8- or 4-pin 12V CPU power connector
- PCIe power connector
- SATA Express/SATA 3 connectors
- M.2 connectors
Headers
- Front-panel header: a group of individual pins for the power button, reset button, hard drive LED, power LED, internal speaker, and case features
- Front panel audio header: powers headphone and speaker ports
- Fan and pump headers: for CPU, system, and water cooling
- USB 2.0, 3.0, and 3.1 headers
- S/PDIF (digital audio) header
- RGB strip headers
External Ports
Your motherboard is the hub that external devices connect to, and its I/O controller manages these devices. Consumer motherboards provide ports that connect a CPU’s integrated graphics to your monitor (useful if you don’t have a discrete graphics card or are troubleshooting display issues), peripherals like a keyboard and mouse, audio devices, Ethernet cables, and more. Different revisions of these ports, like USB 3.1 Gen 2, can allow greater speeds.
Motherboards group external ports on their back panel, which is covered with a removable or integrated “I/O shield” that is grounded due to its contact with an often metal case. This is sometimes attached to the motherboard, or comes separately to be installed when putting together the system.
Peripherals and Data Transfer
- USB port: A ubiquitous port used to connect to mice, keyboards, headphones, smartphones, cameras, and other peripherals. It provides both power and data (at speeds up to 20 GBit/s using USB 3.2). Current motherboards may feature both the classic USB Type-A connector and the slimmer, reversible Type-C connector.
- Thunderbolt™ 3 port: A high-speed port that uses a USB-C connector. Thunderbolt™ 3 technology transfers data at speeds up to 40 GB/s and also supports the DisplayPort 1.2 and USB 3.1 standards. DisplayPort support makes it possible to “daisy chain” multiple compatible monitors and drive them from the same PC.
- PS/2 port: A legacy port, this color-coded six-pin connection connects to a keyboard or mouse.
Display
These display ports connect to your motherboard’s onboard graphics solution; a graphics card installed in one of your expansion slots will provide its own display port options.
- HDMI (High-Definition Multimedia Interface): This ubiquitous digital connection supports resolutions up to 8K at 30Hz as of the HDMI 2.1 revision.
- DisplayPort: This display standard supports resolutions up to 8K at 60Hz as of DisplayPort 1.4. Though more common on graphics cards than motherboards, many boards feature DisplayPort support through their Thunderbolt™ 3 port.
- DVI (Digital Video Interface): A legacy port dating back to 1999, this digital 29-pin connection can be either single-link or higher-bandwidth dual-link DVI. Dual-link supports resolutions up to 2560 × 1600 at 60Hz. It easily connects to VGA with an adapter.
- VGA (Video Graphics Array): An analog 15-pin connection with support for resolutions up to 2048 × 1536 at an 85Hz refresh rate. This legacy port is still sometimes seen on motherboards. Often suffers signal degradation with higher resolutions or shorter cables.
Audio
The front of a PC case often features two analog 3.5mm audio ports labeled for headphones (headphone out) and a microphone (mic in).
The motherboard’s rear panel usually has a bank of six color-coded and labeled 3.5mm analog audio ports for connecting to multichannel speaker systems.
Your motherboard may also feature S/PDIF (Sony/Philips Digital Interface) connectors, such as a coaxial and optical audio port, that work with digital speakers, home theater receivers, and other audio devices. This can be a useful option if the device you’re using doesn’t support audio transfer via HDMI.
Networking
Most consumer motherboards include an RJ45 LAN port, which can connect to your router or modem via Ethernet cable. Some boards feature dual ports for use with a Wi-Fi antenna, as well as advanced connectivity features, such as dual 10-Gigabit Ethernet ports.
What’s a PCB?
It’s helpful to know a few basic terms related to motherboard manufacturing, as manufacturer ads and manuals often reference their methods of PCB construction.
A modern motherboard is a printed circuit board (PCB) made of layers of fiberglass and copper, with other components mounted on it or socketed into it.
Modern PCBs usually have around 10 layers, making them much more densely interconnected than they appear on the surface.
Each conductive “trace” — the visible lines covering the surface of the board — is a separate electrical connection. If one of these traces gets damaged, the circuit is no longer complete, and motherboard components will cease to function properly. For example, if a trace leading from a PCIe link to the PCH is deeply scratched, the PCIe slot may no longer power the expansion card installed in it.
After conductive traces are created via chemical etching, manufacturers add the solder mask, a traditionally green polymer coating that helps prevent oxidation. It also helps prevent handling damage, ensuring that traces won’t be disrupted by a minor scratch or bump as you install the motherboard in its case.
What Else Do Manufacturers Add?
Though motherboard manufacturers don’t create their own chipsets, they make countless decisions involving manufacturing, aesthetics, and layout, as well as cooling, BIOS features, Windows motherboard software, and premium features. While the range of these features is too wide to fully cover, common additions fall into a few general categories.
Overclocking
High-end motherboards often provide automated testing and tuning to overclock your CPU, GPU, and memory, providing an easy-to-use alternative to manual adjustment of frequency and voltage numbers in the UEFI environment. They may also feature an onboard clock generator for fine control of CPU speed, an enhanced VRM (Voltage Regulator Module), extra thermal sensors near overclocked components, and even physical buttons on the motherboard to start and stop overclocking. You can learn more about overclocking your PC here.
Cooling
Motherboard components such as the PCH and VRM generate significant heat. To keep them at safe operating temperatures and prevent performance throttling, motherboard manufacturers install a variety of cooling solutions. These range from the passive cooling provided by heatsinks to active solutions, such as small fans or integrated water cooling.
Software
Motherboard software suites make it easier to manage your motherboard within Windows. Feature sets vary between manufacturers, but the software may scan for outdated drivers, automatically monitor temperatures, safely update the motherboard BIOS, allow easy adjustment of fan speeds, offer more in-depth power-saving profiles than Windows* 10, or even track network traffic.
Audio
Advanced audio codecs, built-in amplifiers, and enhanced capacitors can improve the output of onboard audio systems. Different audio channels may also be separated in different layers of the PCB to avoid signal interference.
Construction
Many manufacturers advertise PCB construction techniques said to help isolate memory circuits and improve signal integrity. Some motherboards also add extra steel plating on top of the PCB to protect connectors or support the graphics card (usually secured with a simple latch).
RGB Lighting
High-end motherboards often provide RGB headers to power an array of LED lights with customizable colors and effects. Non-addressable RGB headers power LED strips that display a single color at a time (with varying intensities and effects). Addressable RGB headers power LEDs with multiple color channels, allowing them to display several hues at once. Built-in software and smartphone apps typically make configuration of LEDs easy.
Make Your Choice
Whether you're planning your next build or upgrading your current gaming PC, understanding the components of your gaming motherboard is crucial. Once you know what everything does, you’ll know how to choose a gaming motherboard that suits your build.
You need a socket that matches your CPU, a chipset that maximizes the potential of your hardware, and finally a feature set that matches your computing needs. Take the time to list out several compatible motherboards and compare their key advantages before making a decision, and you should find exactly what you are looking for.