How to choose a motherboard: chipset and board size explained

The four figures that decide whether it builds

Everything else on the spec page is about how convenient the machine will be. These four are about whether it works.

1. 1Socket — has to match the CPU. See What is a socket?
2. 2Memory type — DDR4 or DDR5; a board takes one only. See DDR4 vs DDR5
3. 3Board size — ATX / mATX / ITX, and the case has to accept it
4. 4M.2 slots and SATA ports — the ceiling on how many drives you can fit

What a chipset is, and how much it matters

The chipset is the chip on the board that handles everything not wired straight to the CPU — USB ports, SATA, the remaining PCIe lanes. Its name is a letter and a number: B650 on AMD, B760 on Intel.

The letter is a rough tier. A is entry level, B is the mid-range most people buy, and AMD’s X and Intel’s Z are the top tier: they unlock CPU overclocking and provide more connectivity.

If you are not overclocking, a B-tier chipset is enough for almost everything. The extra money spent on an X or Z board usually comes back as ports you never use.

Board size: the figure that has to match the case

A case states the board sizes it accepts, and it usually accepts several — a case that takes ATX generally takes mATX and ITX too, though not the other way round. Cooler Master MasterBox NR200P takes ITX only, while Lian Li Lancool 216 goes from E-ATX all the way down to ITX.

The overlooked limit on an ITX board is that it has only 2 memory slots — ASRock B650I Lightning WiFi, for instance. So 32GB means buying a kit of two 16GB sticks in one go; you cannot start with 16GB and top it up later as you could on a four-slot board.

M.2 slots and SATA ports are the drive ceiling

An M.2 SSD plugs straight into the board with no cable, so the number of M.2 slots is the number of those drives you can fit. SATA drives connect by cable to the SATA ports on the board.

The counts really do differ between boards. Gigabyte B650 EAGLE AX has 3 M.2 slots; ASRock B650I Lightning WiFi has 2 M.2 slots and 2 SATA ports — an ITX board has already spent its area on being small, so having fewer is normal.

What about the rest of the spec sheet?

• Maximum memory capacity — Gigabyte B650 EAGLE AX takes up to 256GB, far beyond anything a home machine needs. Do not decide on this figure.
• Maximum memory speed — relevant if you are buying high-frequency memory, but the difference you can feel is small. The reasoning is in DDR4 vs DDR5.
• Built-in Wi-Fi — worth it if the machine is not next to the router. It costs little extra, and adding a card later is more trouble.
• Power delivery (VRM) — matters for a power-hungry CPU you intend to overclock. For a mid-range CPU on a B board, it is not something to worry about.