16x16 vs 8x8

[Bopster]

I am trying to decide between 2 Motherboards.
The Gigabyte GA-P67A-UD7-B3 or theGigabyte GA-P67A-UD5-B3
I need a board that allows me to use a needed PCI card along with 2 double space graphics cards.
My build:
MOTHERBOARD Gigabyte GA-P67A-UD7-B3
CPU Sandy Bridge 2600k
RAM CORSAIR Vengeance 8GB
SSD OCZ Vertex 3 120 GB
HDD WD 1.5 Cavier Black x2
CPU COOLER Thermalright Silver arrow
VIDEO CARD Sapphire HD6950 2GB x2 in Crossfire
BLU RAY BURNER LG
BLU RAY READER LG
POWER SUPPLY CORSAIR AX1200

The Vertex 3 and the motherboards are right around the corner. CPU will be bought at the same time. Everything else I already bought.

Am I really going to see that much loss with 2 cards running at 8x on the Gigabyte GA-P67A-UD5-B3 as opposed to the dual 16x slots on the Gigabyte GA-P67A-UD7-B3 that has the NF200 chip?
I am going for an O/C of 4.8 or so on air which if I understand correctly from what I have been reading will really help the 6950's.

[wazza300]

You won't see any difference,maybe very slightly at super high resolutions

[Psycho101]

Any difference between 8x/8x will be cancelled out by the slight latency introduced by the NF200, especially with one card in the CPU controlled 16x and another in a 16x supplied by the NF200.

The only time anyone should insist on twin 16x lanes is when using two dual GPU cards.

[noobskie]

Read this:

Conclusion - GTX 480 SLI PCIe Bandwidth Perf. - x16/x16 vs. x8/x8 | [H]ard|OCP

Now you must consider that the test setup they have, had native pcie lanes instead of interacting w/ the NF200 chip, w/c adds latency.

From what I learned in the article, in single monitor gaming, it wouldn't matter but in eyefinity or nv surround it sometimes will!