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Bitcoin => Bitcoin Technical Support => Topic started by: sohum on June 29, 2011, 03:24:49 PM



Title: Only seeing one GPU on 6990.
Post by: sohum on June 29, 2011, 03:24:49 PM
I have been reading the forum for some time and also have been mining for a while.  I have one rig with four 6870s and another with two 5830s.  I decided to add a 6990 to my machine (personal use machine not a mining rig) but when I installed it I only see one of the GPUs for mining.  I am running Win7 with the latest Catalyst drivers (11.6 I think) and using poclbm for mining.

Has anyone run into this before?  After searching online for answers I have only seen one post describing the same situation and they claimed that updated drivers fixed their issue.  I wouldn't have purchased a 6990 if I was building another rig but bang for buck since I had my existing system with an open PCI-E slot it was a no brainer but right now it is only performing 340MH/s (I haven't overclocked it yet since I need to get the other GPU working first) which isn't much better than my 5830's that overclocked are doing 300-310MH/s and they only cost $109 compared to the 6990 at $700. 

I see both GPUs in AMD Overdrive but in poclbm there is only the one.

Any suggestions are much appreciated.


Title: Re: Only seeing one GPU on 6990.
Post by: Jack of Diamonds on June 29, 2011, 03:36:48 PM
Happened to me once on first boot when I set up a dual 6990 rig on Windows.

Switch PCI-e lanes with another card, wait until the microcode drivers (not AMD Catalyst)
are auto-installed by the OS.

After that you can put it in the old slot.

Then you should see both cores and any other GPU's on that system.
http://i56.tinypic.com/sou2yg.jpg

If you still fail to see all cores it could indicate the motherboard is not capable of delivering sufficient power to all GPU's on the board.


Title: Re: Only seeing one GPU on 6990.
Post by: sohum on June 29, 2011, 03:54:18 PM
Thanks for the suggestion... I will try that tomorrow morning when I get a chance to work on it and report results for anyone with the same problem or just for interest sake.

The motherboard should be sufficient (MSI 890FXA-GD70) and I took the the other cards out to test it by itself just in case.

If this doesn't work I will move it to ubuntu and see if that solves the problem.

Any other tricks or tests are welcome as I will not be able to attack this problem until tomorrow and I might as well have a list of things to try.

Thanks again.


Title: Re: Only seeing one GPU on 6990.
Post by: IlbiStarz on June 30, 2011, 09:48:06 AM
Go into Catalyst Center and go to the Hardware tab. What does it say for the 6990?

I fixed this by using a dummy plug on the dvi connector.


Title: Re: Only seeing one GPU on 6990.
Post by: sohum on June 30, 2011, 03:58:48 PM
It does say that one of the adapters is disabled.  I have my monitor plugged into the mini-displayport with the mini-displayport-dvi adapter and I have a dummy plug in the actual dvi adapter on the card.  I have moved the connection to my monitor around the four different mini-display ports but it remains disabled in ccc.


Title: Re: Only seeing one GPU on 6990.
Post by: sohum on June 30, 2011, 04:04:19 PM
Thanks for the help... not sure what is different but I uninstalled the drivers, rebooted, re-installed the drivers and now ccc reports them linked.

Wish I had a better explanation for those who run into this in the future but I do not.

Now to see how much overclocking I can do.

Thanks again.


Title: Re: Only seeing one GPU on 6990.
Post by: Fiyasko on July 01, 2011, 05:37:19 PM
 I had simmilar issues. My overall problem was that the stupid card wasnt booting because i didnt have a monitor plugged into it(long story short)