x16x16 PCI slower than x8x8?? p67 a good choice?

[LieutenantFrost]

Need some confirmation on this, saw a thread posted below that said x8x8 was faster than x16x16. Im currently opting for this p67 asus board for this feature

http://www.newegg.com/Product/Produc...82E16813131714

over this one

http://www.newegg.com/Product/Produc...&SID=u00000687

Gonna be running duel 580's in SLI and hoping to do some overclocking too, am I making a good choice?

 

[TakeNoPrisoners]

x16 is faster than x8. That being said it isn't a big difference. A test with dual 6990's 16x vs 8x showed little difference. I would feel fine running two 580's on 8x8x.

 

[Zap]

The difference in performance between x8/x8 and x16/x16 is about the same as the difference in performance between a $180 motherboard and a $360 motherboard. That is to say, about none.

Note that all of these boards shoehorns whatever PCIe lanes they give to the graphics card down to only 16 lanes once it reaches the CPU, so they end up pretty much the same. It can be argued that more lanes = better in some circumstances, but can also be argued that the NF200 chip used to provide those extra lanes adds in a bit of latency.

Thus, flip a coin. Any performance differences, real or imagined, will barely be measurable and will NOT be noticed by a real person in a real game.

 

[LieutenantFrost]

Zap, that being said

Would you go for the p67 or the z68?