Enabling Second ATI card

[dan]

I have two boxes I crunch on. I put my 5870 in a box that already had a 3870 in it. Now the 3870 is disabled. Anyone know how to get the second ATI card running. I'm not doing CF, it just comes up in ccc as disabled.

Thanks,

Dan

[zombie67]

I think you need a monitor or dummy plug attached to the second card.

[Fire$torm]

I think you need a monitor or dummy plug attached to the second card.

Yep, zombie is right. If you have a monitor with multiple inputs you can connect the card to one of those. That is how I have my 4850's set up in my desktop.

[Gopher_FreeDC]

Or an SLI cable.

[dan]

Thanks all! I may just go with the dummy plug. Looks pretty easy to make.

Dan

[Maxwell]

Or an SLI cable.
I believe the problem with running the two cards in Crossfire is that they will specifically "lock out" some of the GPU memory on the better card so that it will match the lower card. I seem to recall reading that somewhere...

[dan]

Well the dummy plug gets the second GPU running. However, it uses both GPUs on the same work package. The problem is that now DNet takes 17 minutes vs 15 minutes per work package. Any suggestions?

Thanks,

Dan

[Maxwell]

Well the dummy plug gets the second GPU running. However, it uses both GPUs on the same work package. The problem is that now DNet takes 17 minutes vs 15 minutes per work package. Any suggestions?

Thanks,

Dan
The issue is that DNETC splits a WU across all available GPUs. Since the 3870 is so much slower, it's taking longer. And I would bet that if you check the load on the 5870, it is sitting idle for quite a while during those DNETC WUs...

My advice: disable the 3870 when crunching DNETC. Enable it when crunching MW or Collatz.

[joker]

Would the 3870 slow down the 5870??? I have run pretty much both of those cards. The 3870 got about 20K a day while the 5870 (an oc'ed 5850 that is faster then most stock 5870's) gets about 270K a day. Could having them in the same box be a bad thing?

Dang it! You beat me to it by a minute Max.

[Maxwell]

Would the 3870 slow down the 5870??? I have run pretty much both of those cards. The 3870 got about 20K a day while the 5870 (an oc'ed 5850 that is faster then most stock 5870's) gets about 270K a day. Could having them in the same box be a bad thing?
For DNETC, yes - it would be like me running a series of hundred yard sprints with Usain Bolt. We start at the same time, he finishes quickly, then stands around waiting for me to finish. He still runs just as fast, but spends a lot of time standing around waiting for me...

[dan]

The issue is that DNETC splits a WU across all available GPUs. Since the 3870 is so much slower, it's taking longer. And I would bet that if you check the load on the 5870, it is sitting idle for quite a while during those DNETC WUs...

My advice: disable the 3870 when crunching DNETC. Enable it when crunching MW or Collatz.

Yep I did notice the last 4 minutes the 5870 sitting idle. I only crunch DNet on this box and was hoping to have them run as discrete processors.

Guess it's time for a third computer :-)

[joker]

We start at the same time, he finishes quickly

How can I twist that one............. =))

[Maxwell]

Yep I did notice the last 4 minutes the 5870 sitting idle. I only crunch DNet on this box and was hoping to have them run as discrete processors.

Guess it's time for a third computer :-)
Is your box with your CUDA card running Win7? Because you should be able to throw one of the ATI cards in there...

[dan]

Is your box with your CUDA card running Win7? Because you should be able to throw one of the ATI cards in there...

Ya. I can try that. It would take some wiggling since the cuda card takes three slots. I think I tried it before and got blank screens out of both cards.

Thanks,

Dan

[Maxwell]

Ya. I can try that. It would take some wiggling since the cuda card takes three slots. I think I tried it before and got blank screens out of both cards.
Try putting the 3870 in the top slot and plugging the monitor into it, and nothing into the CUDA card. I think that's how others have mixed and matched...

[Fire$torm]

Try putting the 3870 in the top slot and plugging the monitor into it, and nothing into the CUDA card. I think that's how others have mixed and matched...

+1. Yeppers, that be the way to sri lanka.