PsyKhiqZero :
The toms bench you provided is comparing pci-e 1.0 spec at 8x to pci-e 2.0 at 16x. I have no idea why you would want to compare the two in that way.
You simply don't know what you're talking about.
In fact, half of the guys in this thread are speaking out of ignorance. The Tom's Hardware P55 CrossFire articles were all run at PCIe 2.0 for both x8 and x16, and
get this:
High-end Micro ATX and high-end ATX are pretty much the same thing, quality and engineering wise. You can get a top Micro ATX board such as the Rampage II Gene, with two full-bandwidth PCIe 2.0 x16 slots, that pretty much stomps on big boards such as the P6T Deluxe.
You don't have to take my word for it, try reading some reviews instead.
To the OP: If you want dual PCIe 2.0 x16, look at X58 (Intel) or 790FX (AMD) motherboards. Those remain the gold standard no matter how many slots the board has.