6950 Crossfire EXTREMELY poor performance

Gipswasser

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Hi guys,

Could not find any solution so i post my little problem:

I have just added a second 6950 1gb to my system and the performance went below ridiculous. Crysis Warhead is under 10FPS and Crysis 2 (DX11) under 5 in avg (1920x1200).

I have tried out both cards individually (physically removing the other card) and they are just fine (reasonable fps). FPS are also as expected with crossfire disabled.

They are of different make (ASUS and HIS) but both have same clock speed.

I did not have any problems with previous generations of crossfire cards.

NOTE: FurMark produces 60ish fps in 1080p with both cards working fine...

Thank you fro any ideas on the matter :)


System:

CPU i5 2400 (@3.1)
MB Intel DP67BG
RAM 8gb Corsair
 

Lyden

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1. Sorry to be blunt here but AMD crossfire drivers suck. Always have. Never met anyone who has had major success with their CF drivers.
2. Your motherboard supports SLI: x8, x8 mode. Try getting a board with SLI: x16, x16 before calling it quits.
3. Without actually getting on your computer and looking at the driver myself, I can't REALLY give a whole lot of advice. You could call AMD? Worth a shot.
 

PartialGenious

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I mean have you been over the obvious solutions. You have enough power to push the two cards? You have the bridge installed? Both cards show up in your device manager? Have you checked temps on the two cards? Give us more details about your system so we can get a better understanding of what is going on.
 

Gipswasser

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Before I start sounding ungrateful: Thanks for ALL who took the time to reply...

Here is how it stands though

Both cards run perfectly fine on FurMark (under 80 degrees both) as I said in the post. Also FurMark shows the performance boost (31fps at 1080 with one card, 59 with two cards). So the cards are working under GL fine. That almost certainly rules out hardware issues.

Yes, before physically switching cards a number of times i did reinstall drivers (in different beta and no beta versions) 3 times).

The 8xPCIe is certainly not the bottleneck for a performance loss like this.

850w Coolermaste should be ok. Admittedly only a bronze one but I know what power problems look like and this is not it

I have been putting together PC's for over 24 years, so I kinda know the basics ;).

Any better ideas?

Thanks again :)
 

PartialGenious

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Have you tried any other games besides Crysis to see if it is specific to one program? I mean your furmark tests I would assume does rule out hardware issues so that only brings us to issues with the driver or the specific game settings.
 

jjtober1

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I would try out RadeonPro, you can try a different crossfire profile, maybe you will have success there. Also you could try driversweeper to remove the old driver before you install a new catalyst if you haven't done that.
Have you downloaded the latest Application profiles to go with your catalyst? That can make a huge difference.
 

deweycd

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I found that the best way of getting my system to work optimally in crossfire was to try different driver versions. Try the one that came with the cards first. I then upgraded by 0.1 of a driver version and benchmarked until I figured out the best setup. This took time but resulted in a very stable system and about 175% preformance compaered to a single card. Crossfire drivers can be fickle but it can work very well and stable. Also, ensure that your driver version and application profile version are the same. Otherwise you may run into issues. They never should have seperated them as they only work well in pairs.

In case your worried, SLI can have the same kind of issues. Also, you don't need to upgrade to a 16x by 16x motherboard to get good results. An 8x by 8x will only be minimally lower performing (less then 5% difference at the most).
 

Gipswasser

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Hmmmmm

Just Cause2 goes will into the 120+ fps ... in may be a thing with Crysis (apparently 1 and 2). Will play around with drivers a bit....
 

Gipswasser

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Have gone back to 10.x drivers now and the results are the same. Crysis 1 and Crysis 2 engines are more or less freezing up in CF (running ok in single card mode).

I am out of ideas...
 

hellspawn360

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I am having the same problem with my 6950's, I have tried installing different drivers, disabling ULPS, and underclocking both cards. Like the OP stated both my cards work fine with crossfire disabled. :\
 

flashfir

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If you read reviews on PSU's you will find out that the quality of a unit is not based on its efficiency at all. That would be coincidental.

Look up your review on your PSU. What is it called? Sites like johnnyguru or hardwaresecrets should have reviews on it or at least you'll find other people who're asking.
They open up the PSU and actually rip it apart to look at all the individual components, rectifiers, capacitors, heatsinks, soldering, etc...

CoolerMaster is good but they make some iffy ones.
 

Gipswasser

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Hm... Just to entertain everybody. The problem solved itself!

I went through another number of driver iterations with the same result. When I went to show a friend how abysmal the FPS were in Crysis 2, the game obliged by showing great 4fps. I then forgot to escape to the menu and let it run. Friend and I kept talking and after circa 5 minutes the framerate started climbing... It went all the way up to 80+. Game runs fine now with the initial drivers and performs at the expected 40+. Roughly 10h of soft and hardware installation... much ado about nothing. Still no idea what the problem is but somehow I care less :).

Thx to everybody who tried to help.

Gips
 
That's more than just crossfire not working or being slow to start. This almost sounds like a priority issue. Windows takes forever before giving the resources to allow Crysis 2 to run.

Other thoughts include folding or bitmining taking over the cards and is slow to give them up, or virus scanners.