I am trying to choose motherboard for the following config.
Processor - i7 2600K
Socket - LGA 1155
Chipset - Intel H67
Feature wise I require,
HiDef gaming & Movie Entertainment support
SATA 6 Gb/s & USB 3.0.
Applying these 3 filters, microCenter returned 11 choices.
What should be my criteria for choosing either ATX or mATX?
I understand ATX is slightly bigger than mATX. Hence has room for expansion as it has more slots. I presume price difference will be negligible.
Do correct me if I am wrong.
mATX is just weak. ATX is the way to go. The motherboard I would recommend for the i7 2600K is the Asus P8P67 Deluxe. It's more or less the best motherboard you can get in the price range, and the motherboard shows it. You get 2 x USB 3.0 at the rear, and two more in an expansion box you mount at the front of your PC (like an optical drive). It also sports HD audio at 9 channels, has SPDIF and Optical output for audio, and AFAIK the board has 4 SATA 6GB/s ports. It also has two LAN ports, Firewire, Bluetooth and a few more extra cool features. If you are going to spend money on a new Sandy Bridge CPU, and you want the best, this is more or less it without wasting your money.
mATX is not a bad choice, it just needs to be selected for the right use. It works really well as an HTPC board and you can get mATX boards that have most of the features as the ATX version, but just a few less PCI-E slots.
If you have no plans to use X-fire or SLI, an H67 would be fine. They tend to be 30-40% cheaper. If you study and compare the details and features of several different boards, your choice can be narrowed by your needs. Most online retail sites have a side-by-side comparison feature. It's a good tool to spot differences in seemingly alike boards.