Added second 5850 this morning, no benefit - troubleshooting

[phr4n]

I'm writing this up on here on behalf of a friend in the interest of troubleshooting his negligible performance difference since he installed a second 5850 into his system.

I7-920
Gib EX58-UD3R
2x 5850 (different brands)
Antec 650
Dual Monitors

We've gone through connections, bridge, fully reinstalled drivers.

Tried BF3, CSS and Company of Heroes.

BF3 FPS counter showed 80-90 FPS but the game felt like 10 - 30 (no change in settings)

Other games showed no difference.

GPU-Z shows crossfire enabled. Any pointers?

 

[ThePengu1n]

Make sure you have the latest drivers (11.10 I think) and get the latest CAP as well (11.9 CAP 4)

 

[harmony]

CSS = Counter Strike Source? This engine doesn't use much GPU power and you won't see much scaling there.

BF3: current AMD driver is bugged, and 1GB vram is supposed to be choppy with 4xMSAA Ultra 1080p, in the vram-hungry areas, e.g. 64-player maps.

Try some synthetic benchmarks like 3DMark11 so you can tell if the CrossfireX is working or not. Also you can enable the CrossfireX logo through the small CCC icon in the lower right corner of the Windows Taskbar.

 

[Mattuk69]

I've already got a thread up about this. I've brought a different motherboard, better PSU, reinstalled drivers, reinstalled OS and looked for answers all over the net.
I can honestly say crossfire 5850 is trash. Tell your friend to sell one of the 5850's. Use the other untill the 7000 series are out then sell that one.

The only game Crossfire has worked for me is Dirt 2. Every other game has had worse performance, no effect or 5-10fps increase.