The motherboard is the part people either ignore or overspend on. It does not make games faster, so a $180 board and a $450 board can post the same frame rate, yet the wrong board can leave you without a slot for a second SSD, without a way to update the BIOS for a new chip, or with a graphics card hanging over the M.2 you wanted to use. We choose boards for custom builds every week at our Somerville shop. Here is how we do it in 2026: what AMD's B850, X870 and X870E chipsets really change, where Intel's Z890 and B860 land, the specs that matter for a gaming PC, and the ones that only matter for the price.
All four current chipsets take the same CPUs, from the Ryzen 5 7600X to the Ryzen 7 9800X3D and Ryzen 9 9950X3D2, and the same DDR5 memory. The differences are lanes, ports and rules, from AMD's official chipset comparison.
| Chipset | Graphics slot | Primary M.2 | USB4 (40 Gbps) | Overclocking | Who it is for |
|---|---|---|---|---|---|
| X870E | PCIe 5.0 x16 required | PCIe 5.0 required | Required | CPU and memory | Two chipset dies for the most USB and PCIe lanes. Builds with several Gen 5 SSDs, capture cards or 10 GbE. Typically $350 and up. |
| X870 | PCIe 5.0 x16 required | PCIe 5.0 required | Required | CPU and memory | TechSpot's description is the honest one: essentially the older B650E with USB4 made mandatory. Buy it for the USB4 ports, not for speed. |
| B850 | PCIe 5.0 x16 on most boards (optional in the spec) | PCIe 5.0 required | Optional | CPU and memory | The gaming sweet spot. Same CPU support and same game performance as X870 for less money. |
| B840 | PCIe 3.0 | PCIe 3.0 | No | No CPU overclocking | Office boxes and the cheapest possible builds. PCIe 3.0 throttles a modern graphics card's link and a Gen 4 SSD; we do not use it for gaming. |
Feature requirements from AMD's Socket AM5 chipset page and TechSpot's guide to AM5 chipsets (February 2025). Individual boards can exceed the minimums, so read the board's own spec sheet, not just the chipset name. Previous-generation X670E, X670, B650E and B650 boards still run Ryzen 9000 after a BIOS update and remain fine choices at a discount.
Intel's Core Ultra 200S chips (Core Ultra 5 225F and 250K Plus through the Core Ultra 9 285K) use the LGA1851 socket and the 800-series chipsets listed on Intel's product database.
| Chipset | CPU overclocking | Memory overclocking (XMP) | Connectivity | Who it is for |
|---|---|---|---|---|
| Z890 | Yes | Yes | The most chipset PCIe 4.0 lanes and USB ports, Thunderbolt 4 on many boards | Overclockers, and builds that want every port. Prices start above most B850 boards. |
| B860 | No | Yes | Fewer lanes and ports, still PCIe 5.0 graphics and Gen 5 M.2 from the CPU | The right board for a Core Ultra 5 250K Plus gaming build. XMP memory profiles work, which is all most people need. |
| H810 | No | Limited | Basic | Office machines. Skip it for gaming. |
One platform note before you choose a socket: AMD has said its next desktop chips are planned for AM5, so a B850 board bought today has a real upgrade path. Intel has not confirmed a successor on LGA1851. That is part of why our mid-range Intel builds lean on the value of the chip itself, as we covered in our Core Ultra 5 250K Plus review, rather than on the board's future.
Chipset first, then these six things, in this order.
Two M.2 slots is the practical minimum for a gaming PC in 2026, one for Windows and games, one for the drive you add in two years. Check the generation on each slot (the primary is PCIe 5.0 on every current chipset; secondary slots are often 4.0, which is fine) and read the fine print on lane sharing: on many boards, filling a particular M.2 slot disables a SATA port or drops the second PCIe slot to fewer lanes. The spec sheet says so in a footnote; the box does not.
Every board maker has one under a different name: ASUS USB BIOS FlashBack, MSI Flash BIOS Button, Gigabyte Q-Flash Plus, ASRock BIOS Flashback. It lets the board update its firmware from a USB stick with no CPU or memory installed. New CPUs ship faster than boards on shelves get updated, and a board that needs a newer BIOS to recognize your chip will simply not boot. With the button, that is a five-minute fix. Without it, it is a trip to a shop with an older CPU on hand. We will not put a board without one in a customer build.
Four DDR5 slots is standard on ATX boards; some compact and high-end boards use two, which gives up expansion but often runs memory more reliably. Either way, buy the kit from the board's qualified vendor list (QVL). AM5 in particular is picky, and a kit that is not on the list can boot at a lower speed or not at all. We wrote up a real case in When a Custom PC Won't Boot Right, and our DDR4 vs DDR5 guide covers which kit to buy.
Most B850 and B860 boards now include WiFi 7 and a 2.5 gigabit wired port. The non-WiFi version of the same board is sometimes $20 cheaper, which is worth it if the PC will sit on a cable forever. Adding WiFi later costs more than that $20.
Count the USB ports you will actually plug in: keyboard, mouse, headset, webcam, controller dongle, phone cable, printer. Budget boards can ship with as few as six. Check for a front-panel USB-C header if your case has a USB-C port on the front, and for enough fan headers to run the case fans without splitters.
The voltage regulator feeds the CPU, and board makers advertise phase counts the way car makers advertise horsepower. Tom's Hardware tested this directly in July 2026, running flagship CPUs on budget and high-end boards and measuring VRM temperatures, and found that mainstream boards do not throttle even the top chips. A mid-range B850 board like the MSI MAG B850 Tomahawk Max WiFi II lists a 14+2+1 phase design with 80 A stages, which is more than a Ryzen 7 9800X3D will ever ask for. Unless you are pushing a 16-core chip with manual overclocking, the VRM on any board from a major brand in the $180 and up range is not the reason to spend more.
Representative picks by build, cross-checked against Tom's Hardware's best motherboards guide (updated August 4, 2026). Specific models change with stock; the tier does not.
| Build | Board tier | Why |
|---|---|---|
| AM5 gaming, $1,000 to $2,000 (Ryzen 5 7600X to Ryzen 7 9800X3D) | B850 ATX with PCIe 5.0 x16, two or three M.2, WiFi 7, flash button | The MSI MAG B850 Tomahawk Max WiFi II and ASUS TUF Gaming B850-Plus WiFi are the type of board we mean. Same game performance as X870 for less. |
| AM5 high-end (Ryzen 7 9850X3D, Ryzen 9 9950X3D2, RTX 5080 or 5090) | X870 or X870E | USB4 for fast external storage and capture, more lanes for a second Gen 5 drive, and stronger power delivery for the 16-core parts in all-core work. |
| Intel mid-range (Core Ultra 5 250K Plus) | B860 with WiFi | XMP works, PCIe 5.0 graphics and Gen 5 M.2 come from the CPU, and the board costs less than Z890. CPU overclocking is not worth the money on this chip. |
| Intel high-end (Core Ultra 9 285K) | Z890 | For the extra lanes, Thunderbolt and the option to tune, which is what a buyer at this tier usually wants. |
| Compact build | Micro-ATX B850 or B860, or Mini-ITX | Fewer slots by design. Our case sizes guide covers what fits where. |
| Skip | B840, H810, any board without a flash button, any board with one M.2 slot | PCIe 3.0 holds back current parts, and the missing features cost more to work around than they save. |
⚡ Want the board matched to your CPU, case and memory before you buy? Send us the parts list or bring the PC in. We check the socket, the BIOS version, the QVL and the physical fit, then quote the build.
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Both take the same AM5 CPUs and DDR5 memory and support CPU and memory overclocking. X870 makes USB4 ports and a PCIe 5.0 graphics slot mandatory; B850 requires a PCIe 5.0 M.2 slot, leaves USB4 optional, and most B850 boards still include a PCIe 5.0 graphics slot. In games the two perform the same. Buy X870 for USB4, and X870E for extra lanes, otherwise B850.
No. The motherboard does not change frame rates as long as it runs the CPU and memory at their rated settings. Tom's Hardware's July 2026 VRM testing found mainstream boards do not throttle even flagship CPUs. Extra money buys ports, slots, USB4, better audio and lighting, not performance.
A B850 board from a major brand with a PCIe 5.0 x16 slot, at least two M.2 slots, WiFi 7 and a BIOS flash button covers the 9800X3D completely, and Tom's Hardware's 2026 guide names boards like the MSI MAG B850 Tomahawk among its picks. Move to X870E only if you need USB4 or several Gen 5 drives.
Only if you plan to overclock the CPU or want the maximum number of lanes and ports. B860 supports XMP memory profiles, PCIe 5.0 graphics and a Gen 5 M.2 slot from the CPU, which is everything a Core Ultra 5 250K Plus gaming build needs, for less money.
The board's BIOS is older than the chip. Boards sit in warehouses while CPUs launch, and a board that does not recognize the processor will not post. A BIOS flash button (USB BIOS FlashBack, Flash BIOS Button, Q-Flash Plus, BIOS Flashback) fixes this from a USB stick without a working CPU. That is why we only install boards that have one.
Yes, after a BIOS update. The previous-generation AM5 chipsets support Ryzen 9000 and the X3D parts once the firmware is current, and they are often cheaper than B850. Confirm the BIOS version or the presence of a flash button before buying, and check the board's CPU support list.
Bring your parts list or your budget. We will pick the board that fits the CPU, the case and the memory, update the BIOS, and build it so it boots the first time.
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