Motherboard Sizes: Understanding E-ATX, ATX, mATX, and mini-ITX When building a PC, choosing the right motherboard size is crucial for ensuring compatibility, upgradability, and performance.

Motherboard sizes explained There are four motherboard sizes available in 2025 from major manufacturers such as Asus, Gigabyte, and MSI, among others. These are Mini-ITX, MicroATX, ATX, and E-ATX.

Both are E-ATX motherboards with shared features such as one-touch overclocking and RGB lighting. The ROG Strix X399-E and Prime X399-A support 3-way SLI and Crossfire configurations.

The B650MP-E features a wide range of USB and connectivity options on its rear I/O with 4x USB 3.2 (Gen1) ports, 1x USB 3.2 (GEN2) port, 1x USB 3.2 (GEN2) Type-C port and 2x USB 2.0 ports.

ASRock's X670E Taichi jams in about everything you'd want from an AMD AM5 motherboard for years to come. Just be sure that this big E-ATX board fits in your case—and your budget.

Testing Chieftec's APEX ATX case, I used the Intel Core i5 12600K on a Z690 AORUS Pro motherboard. For the memory, two DDR5 sticks of Corsair Dominator Platinum RGB ran at DDR5-7200M/T.

The board is E-ATX, meaning it will be larger than your typical ATX motherboard, with measurements of 277×304.8mm (10.9×12 inches), so case size will be important.

Micro-ATX form factor Support for AMD AM5 Ryzen 7000 CPUs 16+2 Phase Design with 110A per stage DDR5 RAM, dual channel up to 2 DIMMs (up to 64GB) 1x onboard M.2 slot (PCIe Gen 5) 2x M.2 slots on ...

If that’s not enough, it’ll also house an E-ATX motherboard, the latest high-end graphics cards, and even supports a vertical GPU mounting bracket (sold separately). Antec P20CE Hardware Support ...

The full tower case has plenty of room for today's most powerful components (max compatibility specs to follow, below) so as well as an E-ATX motherboard you will be able to pack in a 420mm liquid ...

Dark Base 900 will take E-ATX and has lots of 3.5" drive sleds. Suspect the Antec P101S is out, as looking at pictures full E-ATX support likely requires removing the drive caddies.