ATX VS. Micro ATX

What's the difforence between the Micro ATX and a ATX? What one is more common/ best to get?

the difference is mainly size, MATX missing the extra 3 pci/pice slots the full atx board has, but being part of the same specification MATX will fit and mount properly in a full ATX case, an issue which used to be but now is no longer around is the fact MATX boards used to be cheaper, which means subpar comments, but that is no longer the case in most situations so it is irrelevant.

the best one to get depends on your needs/personal choice/budget/upgrade path and maybe even a case you already own.

If you're building a small PC or HTPC, micro is probably the best choice for small size. (ITX is even smaller) But for a general desktop build, standard ATX would have more slots and be more upgradeable.

More on sizes can be found at http://en.wikipedia.org/wiki/ATX#Variants

Never had a mATX match an ATX with regard to OC potentials. There are a few "high-end Enthusiast" mATX boards, but you can get equivalent performance from a cheaper ATX MoBo IMO. More room for Power Phases is also a plus...

Like Randyman said, they usually come with less mosfets for controlling the power to the CPU. Since companies figure those buying ATX are looking for a stock/htpc type computer and don't need to spend the extra $30-50 for increased overclocking potential. This isn't to say that mATX boards can't overclock well, as I've seen plenty of people getting good clocks on a lot of different CPUs.

More than likely, you just won't be able to use high voltages and overclock your cpu to "unsafe" levels. Hitting a stable standard overclock is generally pretty easy and you'll probably be hindered by your cooling more than anything. One thing to do before purchasing your motherboard is to research it and see what kind of overclocking options it has.

But to answer your question, mATX is smaller for smaller cases (maybe for a lan computer) and ATX is the standard.