Mini-ITX
A 170 × 170 mm motherboard form factor defined by VIA in 2001. The small standard that became the enthusiast favourite for full performance in a ten-litre case.
The constraints are hard and deliberate: a single PCIe slot, two memory slots instead of four, little room for cooling and fierce competition for the space around the CPU socket. Even so, a full-size graphics card fits in modern SFF cases like the Fractal Terra or NR200, usually via a right-angle riser cable. Boards cost more than ATX equivalents and demand planning around component dimensions, especially cooler height and power supply format (SFX rather than ATX). Originally intended for thin clients and HTPCs — VIA's own boards were passively cooled. Smaller formats exist: Nano-ITX, Pico-ITX and Thin Mini-ITX for all-in-one machines.