MotherBoard Form Factors


Aug 25, 2011
I was studying Motherboard Form Factors in my curriculum and did a bit of research online.
However, most of the explanations were too technical for me to grasp.
I would like the community to help me out with the following Form Factors
1. PC-XT
2. Full AT
3. Baby AT
4. ATX
5. Micro-ATX
6. LPX
7. NLX
8. BTX


which is the currently used form factor???
Thank You
atx and micro atx are current boards; btx is no longer used on newer boards. The rest is for some proprietary boards and obsolete stuff; for example, an old dell is for sale on craiglist for only $15; the reason it's so cheap is that it uses a pentium III cpu and windows 98, and the case won't work with atx unless you physically modify it.
PC-XT Is a really old IBM Machine Type number 5160 released on March 8, 1983

Full AT: Old IBM Motherboard form factor commonly used in the 80's. 12" wide by 13.8" deep.

Baby AT: Old IBM motherboard form factor used in the late 80's and early 90's. 12" wide by 8" deep.

ATX: Most commonly used form factor. Introduced in 95 is still used today. Standard size is 12" by 9.6"

Micro -ATX: Another commonly used current form factor released in 97. 9.6" by 9.6"

LPX: A form factor used in the 90's but was never really common. Used a riser in the center of the board for PCI cards. 12" by 9"

NLX: A newer, smaller upgraded version of LPX. released in 99. 11" by 7"

BTX: Designed to replace ATX in 2005, was adopted by Gateway and Dell for proprietary systems. Was never fully adopted, and ATX variations are still used. Main purpose for design was to help with power issues with Pentium 4 systems.