I am building my new computer for gaming and multitasking. I do not plan to get two GPU's right now, just 1 ASUS 4850. I have picked the following parts
HD WD 640gb Caviar
Memory CORSAIR XMS2 DHX 4GB (2 x 2GB
PSU Corsair VX 550
I am trying to decide which MB to get:
ASUS P5Q - $315 with ASUS 4850, free shipping
ASUS P5Q-E - $344 with ASUS 4850, with $20 rebate and $9.73shipping
I don't mind paying the extra $29 but does the P5Q-E have features to justify the price difference.
There's only one review around that shows the P45's 8X slots cause a bottleneck. Of course, they're also the only site around that's benchmarked multiple 4850s on a P45. So maybe they're right, but many people (including myself) are skeptical, because 8X PCI-E 2.0 slots are pretty darn fast.
Incidentally, I would suggest getting the P5Q Pro. The differences are the P5Q-E basically a third "16X" PCI-E slot (this makes the P5Q-E a 8X/4X/4X board), a couple more MOSFET heatsinks, and another network slot. Unless you have some particular need for any of those things, they're almost certainly not worth $30.
P45 supports 16Gb RAM on some boards, x48 does not.
The P5Q-E has one x16 slot, one x8, and one x4. When operating in crossfire the first and second slots both operate at x8.
Even P45 boards that claim to have two x16, when you read the fine print, say that the two x16 function in "x8" mode when in crossfire. (I would like to challenge that claim by trying to run two PCI-e 2.0 cards in solo mode at x16)
The review here found no improvements in overclocking, but others have found excellent OC ability.
I believe the P45 will prove to be very stable and very durable (depending on the board). It's also the ideal chipset for the casual overclocker, a growing segment.
The verdict is still out on whether it will be a good crossfire board or not.