Crossfire noob, will my system allow it?

[blakphoenix]

I'm looking to get a 2nd 6950 2Gb for my computer but crossfire confuses me somewhat. I am looking to get the card this afternoon so quick replies would be greatly appreciated. Here is my current setup:

CPU: Intel i5-750
Mobo: Gigabyte GA-P55-UD3P
RAM: 8Gb
GPU: MSI 6950 2GB Twin Frozr II
PSU: Corsair HX-620 620W


I'd be getting a MSI 6950 2GB Twin Frozr III as the 2nd card.

Here's the mobo website: http://www.gigabyte.com/products/product-page.aspx?pid=3163#sp what I'm worried about is this line:

"1 x PCI Express x16 slot, running at x16 (PCIEX16) (The PCIEX16 slot conforms to PCI Express 2.0 standard.)
1 x PCI Express x16 slot, running at x4 (PCIEX4)"

Will that limit my 2nd card to terrible speeds or will i get a marked improvement on mt fps? I mainly play BF3 at 2560x1440 and currently sit around 25fps.

 

[nukemaster]

Here is a page with the answer you seek

http://www.tomshardware.com/reviews/pci-express-scaling-p67-chipset-gaming-performance,2887-10.html

There is a performance hit, Still better then one card, but about 10-25% slower then X8/X8. It generally varied from game to game.

The real question is do you need xfire? or is your gaming fine as it is?

 

[blakphoenix]

Thanks very much nuke! It's good to know that crossfire does indeed work, just with a performance hit. I don't NEED it, but i may be able to snag a good deal on the 2nd card and since i game at high resolutions and games will only get more demanding, it seems like a good idea. Then when Ivy Bridge i can get a new mobo & cpu and that upgrade will also increase my gpu performance.

 

[blakphoenix]

as i said, running ~25 fps in bf3 on medium is rather annoying as i really do feel the stuttering effects of the low fps. i do also play eve online with multiple clients (on multiple monitors) and plan to get more gpu intensive games in the future.

 

[blakphoenix]

Best answer selected by blakphoenix.

 

[nukemaster]

as i said, running ~25 fps in bf3 on medium is rather annoying as i really do feel the stuttering effects of the low fps. i do also play eve online with multiple clients (on multiple monitors) and plan to get more gpu intensive games in the future.

Ahh did not see that, nor the very high rez you play at.

Your cpu should also have some overclocking room if you think it will help in the future