Performance issues with CFX'd 685-'s and Eyefinity.

[potentafricanthunder]

Hey, thanks for looking at my post, first off :)

I recently decided to go Eyefinity with crossfired 6850's
I will say that they are NOT the same brand. My first card is the Sapphire 6850...and the second the XFX XXX series (factory OC'd)

The two cards together only get me about 15 frames avg at max resolution in Heaven, which seemed about normal from the benchmarks on here - http://widescreengamingforum.com/article/amd-radeon-6870-6850-review-heaven-demo-dx11

However in any other game (BF3, Just Cause 2, Dirt 3) I seem to max out at around 25 or so. Even the games that are mentioned in the aforementioned review dont run at the same (or close to) FPS as the reviewers's PC, which I know is faster than mine.
What's realistic as far as FPS here.?

Ive tried the Sapphire card alone and get about 30 frames in Dirt3 and different driver versions (10.12 and 11.12). No changes so far.

Here's my setup by the way..

i5-760 @ stock 2.8Ghz
MSI G45-h55
8gb Supertalent DDR3-1333
2x 1.5 TB HDD Spanned (no Raid)

I do have benchmarks to post if it would help anyone help me out :D

[Gilly]

You mean this motherboard right?

http://www.msi.com/product/mb/H55-G43.html#/?div=Basic

And, what PSU are you using?

I don't know just off the top of my head, but depending on resolution the performance you describe in BF3 isn't uncommon.

What resolution are you using? I would guess 3x1080p yes?

It is entirely possible in BF3 you are maxing the video memory of the cards, not sure for the other 2 games.

[Eriol]

Most likely it's a memory bottleneck. At Eyefinity resolutions you quickly go beyond 1GB VRAM so FPS will take a nosedive.

[potentafricanthunder]

Yep. 3x1080

My power suppy is a Kingwin 750w for now. My Corsair blew out on me after 3 years of service.

And yea, that's the motherboard I'm using.