[[File:Atxscale.svg|thumb|ATX motherboard size comparison; rear is on left.
thumb|ATX motherboard size comparison; rear is on left.
In computer design, microATX (sometimes referred to as mATX) is a standard motherboard form factor introduced in December 1997. The maximum size of a microATX motherboard is . However, there are examples of motherboards using microATX designation despite having a smaller size of . The standard ATX size is 25% longer, at .
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).