How to choose a motherboard: sockets and chipsets explained

What's the coolest, most personal part of your rig? It's not the CPU. Those all look the same. It's not the graphics card either. They have more variety than CPUs, but not much. The coolest component of your system—the part with the most personality and style by far, unless you have a fancy custom water cooling loop—is the motherboard. There's one for every use, niche and sensibility, and these days they come in custom colors and patterns. It's hard to believe how many of them are out there.

The array of choices can be bewildering, especially because the most important differences are in function, not aesthetics. Tiny, seemingly insignificant model number differences hide huge disparities in performance potential and hardware compatibility.

We're here to guide you through the chaos and help you pick the right chipset and socket for your choice of CPU and system style. Whether the rig of your dreams is all about gaming, tweaking overclocked hardware, or even speeding through workstation tasks, there's a type of motherboard made especially for you. 

Motherboards don't provide performance themselves, but they enable it by allowing quality components to reach their full potential. That shiny new unlocked processor is wasted on a motherboard that doesn't support overclocking. Even on boards that do overclock, you'll get a lot more reach and a wider stability envelope from a quality board. Here's how to pick the right one for you.

Think about your build style and size

The Complete Guide to PC Gaming

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Custom rigs, especially hand-built ones made for gaming, aren't just about the numbers. Sure, performance is important, but if you're spending the money on a system you'll be using for years, you should be proud of it.

Early in the build process, spend a little time thinking about the look and character of your upcoming PC. Do you want a flashy, LED-soaked screamer or a sleek and silent sleeper? Feel like building a show-it-all full-sized plexiglass tower, or an impossibly tiny silver desktop ingot? Once you have a blueprint in mind, you can start making hardware choices. 

Remember that there are four common motherboard sizes, which fit different sizes cases:

Mini-ITX: The smallest, designed for very compact builds and cases. Typically has only a single PCIe slot, meaning you can only fit one graphics card.

MicroATX: Smaller than your standard motherboard, but with more features and expansion options than mini-ITX boards.

ATX: The standard motherboard size that fits in most PC cases, with multiple PCIe slots, M.2 slots for SSDs, lots of SATA connectors, and other features. For any mid-tower or full tower case, this is the typical choice.

E-ATX: Extended motherboards are most commonly used for high-end CPUs, like Intel's Extreme series. They're more expensive and usually come packed with high-end features. Often requires a large full tower case to fit.

Our guide to the best PC cases has choices big and small, and tells you what size motherboards will fit inside.

Intel or AMD

If you're not sure which processor to pick, head on over to our CPU guide where we break down the choices for every budget and interest so it's easy to select the silicon that's right for you. While your pick here will influence the types of motherboard you can use, don't worry about your choice locking you out of the latest features as it may have in years past. While fans of AMD or Intel may argue over processor supremacy, the motherboard situation is largely equal these days.

By now you should have also selected a graphics card. For gaming rigs, this is the single most important performance component, and the rest of the system should be built around running this GPU at the native resolution of your monitor, with the highest gaming detail levels and framerates your budget can support. This may also dictate certain minimum requirements for components like the power supply, and size of the case, so keep those size and budgetary calculations in mind as you continue.

Motherboard chipsets explained

Chipsets provide the control logic required to make the components of a system work together, from CPUs to storage, and are responsible for the type and number of connectors available on a PC both inside and out. 

Motherboards are identified by the chipsets they are based on, and these names change when major new CPU revisions are released, which happens frequently. That means that at any given time, a few generations of motherboards share the marketplace, adding to the confusion. To help make sense of this, here are the current (as of late 2018) chipsets and the sockets they support.

Intel's new socket. Same as the last one. Almost.

Intel 300 series
Main CPU Socket: LGA 1151v2

Intel's current consumer chipset is home to the 8th generation and 9th generation Core processors (also called Coffee Lake). The Z370 and Z390 chipsets, which support overclocking and Nvidia SLI, are the most popular with enthusiasts with the mainstream H370 and B360 chipsets rounding out the gamer's corner of Intel's lineup. Intel also has its enthusiast X299 chipset, which is for its Extreme series CPUs.

The Z370, Z390, H370, and B360 chipsets support the CPU socket called LGA1151v2. The X299 chipset uses the larger LGA 2066 socket, which accommodates the extra cores and other features found in the Extreme CPUs. The pricey X299 series has a number of improvements over earlier and lesser Intel chipsets, including plenty of lanes for M.2 SSDs, multiple GPUs, faster DDR4 support, more ports, and more.

While the extreme X299 platform has some relevance beyond bragging rights for Intel, it's mostly for non-gaming purposes. Skylake-X CPUs, like the Core i9-7980X, sport up to 18 cores and have I/O lanes aplenty for expansion cards. If you want 10Gb Ethernet, multiple high-end PCIe SSDs, or other expansion cards, and more M.2 slots, X299 might be worth a shot. But with the mainstream platform now supporting up to 8-core CPUs, X299 is primarily for professionals.

The truth is, with Nvidia moving to an NVLink connector, SLI and gaming in general still perform better on the mainstream LGA1151v2 platform. Core i9-9900K through Core i7-8700K have higher clockspeeds and lower memory latency, which benefits gamers. 

There are other extras you might like on X299, though. Most boards will give you all the bling you can handle. From LED light shows to remote-control overclocking panels, you'll find the wildest ideas in Intel's computing world on display here. X299 isn't cheap, but it delivers tomorrow's tech today.

Budget choices: H370 and B360

Drop much lower than $100 and the motherboard market starts to get murky. Cheapo Z370 motherboards cut a lot of corners to push the prices down, but they aren't the only game in town. There's salvation in the form of the H370 and B360 chipsets.

H370 and B360 gaming requires remarkably little sacrifice in either performance or looks. It's a less flexible world, but when it comes to money, the savings multiply quickly. You can skip high-speed DRAM since 2666 MHz is the maximum supported memory speed. You can also forget about Nvidia SLI, not that we recommend multi-GPU these days, though AMD Crossfire setups are still an option if you don't mind a performance penalty.

Another sacrifice is overclocking, but staying at the speed limit and going with a non-K series CPU (for exampe, the Core i5-8400) over an overclockable i7 or i9 (like the Core i7-8700K) will save money that can be redirected toward a higher horsepower graphics card, which is where you'll realize the biggest ROI for gaming.

Intel's latest entry: Z390

Intel motherboards featuring the new Z390 series launched in late 2018, but offer few practical advantages over Z370, which released in 2017. They both support the same LGA1151v2 socket, and a BIOS update is all that's required for the older boards to support the latest round of Intel's Core CPUs. Along with bragging rights, Z390 does bring a few extra ports, native USB 3.1 Gen 2 support, chipset-based wi-fi, and other refinements.

Intel’s 8th generation CPUs and the Z370 chipset motherboards may be the better option for more budget conscious gamers through the holiday season, especially as sales and other discounts sweeten the deal. Z390 and the 9th gen CPUs are the new hotness and carry a price premium.

AMD
Main CPU socket: AM4

AMD is a bit better about socket compatibility and motherboard longevity than Intel. Ryzen's AM4 and Threadripper's TR4 sockets are relatively new, and we expect both platforms to remain active for some time. The 3rd gen Ryzen CPUs should arrive in 2019 and will still work on the 1st gen AM4 motherboards with a BIOS update.

The current enthusiast chipsets for AMD's sockets include the X370 and X470 for Ryzen, and Threadripper's X399. AMD processor compatibility spans multiple product generations, so older Ryzen CPUs work should in later motherboards without a problem, although you'll need to check the manual and update the BIOS to run newer processors on older chipsets. 

Threadripper also sports 64 PCIe lanes and the core counts to back them up, making just about any combination of add-in cards and drives possible. As with the X299 platform, however, for gaming purposes you're almost always better off sticking with AM4. It's not that Threadripper can't play games, but it's not faster than Ryzen and the extra cores aren't put to use in any current games.

Budget choices

At the other end of the price spectrum, AMD offers its own inexpensive AM4 chipsets in the form of B450, B350, A320, and A300 based motherboards. These offer fewer ports than the flagship X470, but the B450 and B350 support overclocking and run the same default memory speeds as the high-end X370 and X470, making them a compelling alternative for Ryzen users looking to save a few bucks but keep some tweaking options open. A320/A300 boards meanwhile are pure budget offerings and lack many extras, and in most cases don't cost much less than B350. We'd avoid A320/A300 if at all possible.

If you don't need absolutely top-of-the-line single-core CPU performance to satisfy your enthusiast urges, and if you're using a more modest graphics card (basically Vega 64 / GTX 1080 or lower), you'll find life with AMD pleasant and inherently more flexible. Cheap and fun are a winning formula.

Picking a motherboard: What do you want from your system? 

The key to navigating the motherboard maze is mapping where you want to take your system. It starts with size. How small does your computer need to be? When it comes to motherboards, bigger is usually better, roughly up to full-sized ATX. Go with the biggest board your case can comfortably accommodate; don't let the novelty of a small board tempt you unless absolutely necessary, or if novelty is the part of the mission plan.

Why? Smaller boards cost more, provide fewer features and just aren't as stable as big ones. Unless there's a specific reason to go ITX, it's better to avoid them for gaming. Larger boards are easier to work with, provide better voltage regulation and offer niceties like room for serious graphics cards, slots for M.2 drives, and extra RAM capacity. You also avoid the skinned knuckles and high blood pressure inherent in every tight build.

For example, ITX boards that feature M.2 slots frequently put them on the backside of the motherboard, so you'll need to disassemble your system to reach them or purchase an enclosure that has a cutout specifically for this purpose.

The “bigger is better” rule erodes for the largest motherboards, as prices for E-ATX and ATX-XL boards and the cases they require skyrocket. Enclosure prices can more than double moving from mid- to full-sized towers, adding significantly to a system's bottom line. Remember to include the hidden expense when buying and building beyond ATX.

The next step is listing all the things you need from a system. What kind of drives are you hooking up? Are you using Ethernet or wi-fi? Are you running more than one graphics card? How big is the CPU cooler? Any motherboard worthy of consideration should accommodate it all with to room to grow. It's easy to be seduced into a high-priced boutique board only to find out the RAM slots are too close to the CPU socket for your cooler, or it has one less USB-C port than you need. When it comes to motherboards, features and stability trump performance claims.

Learning about PCIe lanes

High speed I/O inside a motherboard is limited to the number of PCIe lanes available to the chipset and CPU. The main PCIe slots you plug graphics cards into support x16 speeds, though if you use multiple cards, that can drop the slot to x8 or even x4, depending on the motherboard and the CPU. The good news is you likely won't need to worry about these complexities at all, unless you plan on an Nvidia SLI configuration with 3-4 graphics cards.

Standard Intel desktop processors have 16 lanes for one or two x16 PCIe slots, with more provided by the chipset. This seems like plenty until you remember one graphics card uses up to 16 lanes by itself.

Fortunately, modern high-end chipsets like Intel's Z370 provide another 24 full-speed lanes added to the CPU's for a total of 40, enough to cover various configurations like dual GPUs or exotic M.2 configurations and a huge jump compared to the handful available during the Haswell era. Do note that the chipset to CPU link is only equivalent to four PCIe lanes, however, so it's a potential bottleneck if you run multiple high-speed devices off the chipset lanes.

Intel's X299 with Core i9 CPUs will give you 44 lanes on Skylake-X CPUs like the i9-7900X and newer i9-9900X and above, along with another 24 from the chipset. (Earlier i7-7800X and i7-7820X are limited to 28 PCIe lanes from the CPU.) Keep in mind that while the lanes may be available from the chipset, some boards only provide the physical connectors for a single x16 slot, running any additional full-length slots at x8 or slower.

AMD splits the difference this generation, with 24 total lanes on Ryzen (four for the chipset) and an amazing 64 on Threadripper. Most AM4 CPUs provide four PCIe lanes for a dedicated M.2 slot, a nice advantage for the mainstream platform.

The main takeaway here is that the performance drop from x16 to x8 is unnoticeable in gaming and most workloads. If you really want a deep dive into PCIe, check out this video.

That covers the basics. Plan your build in terms of size as well as aesthetic, and then choose the chipset that will best fit the needs of your CPU and PC. And now that we've covered the basics, you're ready to go shopping! Head on over to our guide to gaming motherboards to get you started on finding the right motherboard for your build, and we've also got separate Z370 and X299 guides for deeper dives into those chipsets. Happy hunting!