Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

What is the difference between ATX and micro ATX motherboard or in others?

Which is better?

If cost is not a problem which I should buy?

share|improve this question
up vote 3 down vote accepted

The only real difference is size and shape, and by extension the number of PCI and PCI Express slots that are available. The form factor does not govern the number of expansion slots on a board though, so be careful and read the spec sheet for any board you are considering, as a cheap manufacturer of a full ATX board might give you the exact same amount of slots as a cheaper mATX.

You should buy one that fits your need, budget and -most importantly- case.

share|improve this answer

The typical microATX board has either 4 PCI slots or (3 PCI slots and an AGP slot). The typical ATX board adds another two slots. An older ATX or even mATX board may have an ISA slot or two rather than some of the PCI slots. Depending on the model, both types of boards may have either ob-board video or an AGP slot or both. Either type of board may have up to 6 USB ports, if you count the usual pair connected via a cable to the front of the case. Parallel, one or two serial, and PS/2-style keyboard and mouse connectors are almost always present on both types.

A micro ATX board will fit in a full ATX case. An ATX board will not fit in a microATX case. Duh! They have the same mounting screw pattern. A microATX board looks absolutely tiny in a full ATX case, but it does the job when you need a system with a lot of drive bays

share|improve this answer
You should brush up on current tech. Nothing's come with an AGP slot in 5 or 6 years – MDMarra Mar 12 '10 at 12:11
And quite a few boards are ditching the db-25 ports and the ps/2 as well – MDMarra Mar 12 '10 at 12:19
@MarkM: Good points, although I think the AGP slot's final demise was a little more recent. 2 or 3 years ago, one of my friends wanted to upgrade his computer on the cheap and decided to get an AGP board so he could still use his old video card. But he also wanted to be able to upgrade again without having to replace his motherboard, so he found a frankenboard which had both an AGP slot and a PCI Express slot, and could take either DDR or DDR2 RAM. :O – rob Mar 14 '10 at 6:15

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.