Form Factor (ATX, mATX, ITX)
The physical size standard for motherboards, cases, and PSUs. ATX is standard full-size, mATX is compact, and Mini-ITX is for small form factor builds.
PC form factors
ATX (305×244mm) — Standard full-size. Most expansion slots, best airflow, widest component compatibility. Best for gaming and workstation builds.
Micro-ATX (mATX) (244×244mm) — Slightly smaller, fewer expansion slots, but fits in smaller cases. Great balance of size and features for most gaming builds.
Mini-ITX (170×170mm) — Compact. One PCIe slot, two RAM slots. For small form factor (SFF) builds. Requires careful planning around thermals and cable management.
Frequently Asked Questions
Can I use a Micro-ATX motherboard in an ATX case?
Yes. ATX cases accept ATX, Micro-ATX, and Mini-ITX boards. Smaller boards always fit in larger cases (with compatible mounting holes). The reverse is not true — an ATX board won't fit in a Micro-ATX case.