I am partial to the Gigabyte UD4. It has an amazing ports compliment, and a rocking power section, better than either of the Asus's, for stable overclocking.
the gigabyte will overclock the best because of the 16 phase VRM, the asus has the gen 3 pci-e slot but is 12 phase, and asrock is 4 phase and gen 3 pci.
The higher the phase, usually the better the overclocker the board will be.
As of right now, no GPU can fully utilize x16 gen 2 pci
there are some that cost over $300, they just aren't needed. The x58 sabertooth was only 200 and was a great board. no need to overpay if you don't need to
Ok I won't get the asrock. When it comes to the gigabyte I have heard that it has some overclocking thing that can't be enabled, although I don't know what it is called. I can get the Asus cheaper and quicker than the gigabyte. I think I will get the Asus because of this, even though the Gigabyte has better build quality?
"When it comes to the gigabyte I have heard that it has some overclocking thing that can't be enabled"
I don't know what you've heard, but whatever it is it's false, because I have this board, and all overclocking functions work just as you'd expect them to. Maybe your thinking of their X79 UD7 board, which was discontinued because of overheating problems in the VRM section.
I think it would be a mistake to get the Asus board when the Gigabyte board is made better.