P8Z68-V PRO/GEN3

The diference between x8/x8 and x16/x16 is 1%. Any dual gpu configuration have better results then 1 gpu ( the gpu's must be the same ).
In my opinion is better to buy one powerfull GPU. Buy an 7950 or 7970 and your problem is solved. And in the future add another one and your PC will fly.

There are motherboards that will allow you to run two video cards at x16, but they are expensive, around 275-300.

Current GPUs can't saturate PCI Express 2.0 8x, never mind the 16x or Gen 3.0. 16x becomes apparent when you are using PCI Express RAID or SSD. Other than that simply do not worry about 8x Vs 16x for another while (unless you are mad at over-clocking and/or going for coming GTX 690).

I've come to the decision of getting the radeon 7970 with the board and an i7-2600k. For one GPU it seems to run at 16x whereas in the future if I install a second for crossfire, they would both run at 8x each.

I noticed that the intel 1155 chipsets don't have motherboards that have two PCI express slot that can both run at 16x. They seem to always run at dual 8x upon installing a second GPU.

would the regression from 16x for the single to 8x for both still make only a marginal difference as in still 1%?

Otherwise I was thinking of getting a x79 motherboard that can support two GPUs at 16x, although apparently it seems that the processors that go with those are overpriced and don't make that much of a difference in terms of gaming...

Buy what you choosed , not x79. With 7970 it will be a great gaming rig.

so there is hardly any difference between 16x and 8x for a radeon 7970? although this is not the right forum to ask  

Best answer selected by tha1.

This topic has been closed by Nikorr