Crossfire not working correctly

[Technoviking]

Hello,

I have 2 Asus EAH4850s both at stock clocks, which are Crossfired in my system (specs in profile), and both cards only seem to work in CF in 3DMark Vantage and not in anything else. I have tried COD4, UT3, Crysis, pretty much everything, but they will only run off one card.

I've tried using Cat 8.5 (oem drivers), 8.6, hd4800 Hotfix and now 8.7; none of them have made a difference.

Also, CrossfireX is enabled in CCC and I'm using both CF bridges (tried with one and now both, no difference).

Can anyone help me?

Thanks

 

[dirlan]

Hello,

I have 2 Asus EAH4850s both at stock clocks, which are Crossfired in my system (specs in profile), and both cards only seem to work in CF in 3DMark Vantage and not in anything else. I have tried COD4, UT3, Crysis, pretty much everything, but they will only run off one card.

I've tried using Cat 8.5 (oem drivers), 8.6, hd4800 Hotfix and now 8.7; none of them have made a difference.

Also, CrossfireX is enabled in CCC and I'm using both CF bridges (tried with one and now both, no difference).

Can anyone help me?

Thanks

Hi,

Did you check in BIOS if any settings needed to be done ? PCI-E (16x) configuration or so ?

You'll only need 1 bridge. Should be connected at the connectors closest to the back of your case.

Cheers,

Dirk

 

[blobster21]

there might be specific settings for your crossfire to work, did you check in gpu-z if each cards are reported as PCI-E 2.0 X16 working @ X16 2.0 ?



what i'm trying to underline here is the fact that some mobo require crossfired cards to be plugged into slot 1&3, some other accepts crossfire setup based on contiguous slots (1&2 or 2&3). Accidently plugging one of the cards in the PCI-E 4x slot could ( i emphasize the word COULD) give what you describes

Also, according with my own experience, i bridged my cards with the connectors furthest to the back of my case....so there's no rule of thumbs here again.....

good luck, keep us posted !

 

[Technoviking]

Hey guys,

In the BIOS I've changed default video adapter to PEG2 (instead of PEG) and this has fixed most of my problems (also now using only the one CF bridge, thanks Dirlan and Blob).

Crysis now sees both the cards and does use both of them, and my 3DMark Vantage score has also jumped up about 1000 points .

But, still having problems with UT3 and COD4, still seem to be running one card on both, Im not sure what the CF scaling is like in these games but Im sure COD4 w/ Dual Cards turned on should be getting some form of perf increase.

Any ideas what could be causing this?

Also @ Blob,

GPU-Z reports the following for both of my cards:

Thanks alot for your replies

 

[FR@NK]

Why dont you think its working in CoD? You should be getting good frame rates even with just one HD4850.

 

[Kenshai]

Are you basing it by how it looks or are you using fraps or ingame management to view FPS? Also what is your resolution?

 

[Technoviking]

I tried taking a card out to see if COD4 was working with CF, but my fps still stays the same as with 2 cards.

Also, temps/GPU activity dont even move on my second card if I try to run COD4 in CF (with dual cards option enabled in COD4 options)

@ Kenshai

Im using ingame cmd to view my fps, and all of my settings are max with 2x AA @ 1600x1200@75hz

 

[FR@NK]

Try changing the "Catalyst AI" setting in CCC to advanced.

Here is what the GPU usage looks like after playing CoD for afew mins:



This is at 1920x1080 with 2xAA. Notice each GPU is only loaded about 60%. Whats the ingame command to see the FPS? i'll test it some more using only one card and see what the difference is.

 

[Technoviking]

Awesome, after setting Catalyst AI to Advanced, it all started working perfectly.

Both GPUs were sitting at about 50 - 60% load while playing, and FPS picked up a fair bit, Thanks alot FR@NK, would never had thought of that myself

Btw, fps command is cl_drawfps 2

Thanks again.

 

[Kenshai]

Awesome, after setting Catalyst AI to Advanced, it all started working perfectly.

Both GPUs were sitting at about 50 - 60% load while playing, and FPS picked up a fair bit, Thanks alot FR@NK, would never had thought of that myself

Btw, fps command is cl_drawfps 2

Thanks again.

How much did your frames pick up after getting it enabled properly?

 

[Technoviking]

How much did your frames pick up after getting it enabled properly?

From where I was testing, from about 50ish, to 90.