AMD HD 7970 or HD 7950 on PCI-e 2.0x8

[revfarquhar]

Basically, would PCI-E 2.0 x8 negate the differences in raw performance between the HD 7970 and the HD 7950? Especially if I overclocked the HD 7950? I will crossfiring whatever I get with an HD 7970 I already have.


Here are my system specs for reference:
*GIGABYTE GA-P55A-UD4P http://www.newegg.com/Product/Product.aspx?Item=N82E16813128409

*Intel Core i5-750 @ 3.8GHz http://www.newegg.com/Product/Product.aspx?Item=N82E16819115215

*VisionTek AMD HD 7970 @ 1025MHz GPU and 1575MHz GDDR5 http://www.amazon.com/VisionTek-Radeon-PCI-Express-Graphics-900491/dp/B006V6RHVM/ref=sr_1_1?ie=UTF8&qid=1350151238&sr=8-1&keywords=visiontek+7970

*G.SKILL Sniper 8GB (2 x 4GB) DDR3 1600 http://www.newegg.com/Product/Product.aspx?Item=N82E16820231416

*Kingston HyperX 3K 120GBx2 (non-raid) http://www.newegg.com/Product/Product.aspx?Item=N82E16820239045

*PC Power and Cooling Silencer Mk II 950W http://www.newegg.com/Product/Product.aspx?Item=N82E16817703028

*Monitors - 24in 1080p x3 for Eyefinity

 

[nbelote]

If you're doing CF I really think you need to be doing another 7970 if you've already got one, otherwise you very well may cripple yourself if you can't reach the now-theoretical OC you wish to reach.

 

[revfarquhar]

Best answer selected by revfarquhar.