How to force 5870's to operate at 100% activity?

[ensign_lee]

So I set up two 5870's (not crossfired - one powers each monitor) yesterday. Everything was hunky dory yesterday, both of them at 100% activity and at around 75 celcius.

Today, I wake up and they've both lowered themselves to about 80-85% activity according to the catalyst control center and are at around 68 to 70 celcius. Whaaaaat?

How do I fix this? My 5870's are both delivering about 250 Mhash/s instead of the 300+ that I was expecting. I want that extra 100 Mhash/s!

Any ideas?

[ensign_lee]

Update: A restart seems to have done the trick???

What could have caused this in the first place? Ideas? 

[grndzero]

Update: A restart seems to have done the trick???

What could have caused this in the first place? Ideas?  

Windows 7 Aero interface? General Windows slowness? Crappy ATI drivers?

[Tukotih]

Update: A restart seems to have done the trick???

What could have caused this in the first place? Ideas?  

Windows 7 Aero interface? General Windows slowness? Crappy ATI drivers?

^ What he said. Except Aero.

[Inaba]

Update: A restart seems to have done the trick???

What could have caused this in the first place? Ideas? 

Sounds like they are overheating.  What is the temps of the cards?

[rezin777]

Sounds like they are overheating.  What is the temps of the cards?

...

both of them at 100% activity and at around 75 celcius.

Today, I wake up and are at around 68 to 70 celcius.

[Convery]

Dummy plugged?

[Inaba]

Sounds like they are overheating.  What is the temps of the cards?

...

both of them at 100% activity and at around 75 celcius.

Today, I wake up and are at around 68 to 70 celcius.

I'm not sure what you're trying to say.  My original statement still stands.  It sounds exactly like the card is throttling from overheating.  Though I do admit that if the temp is actually 70C and not closer to 90C, it's a bit less likely.  However, if the card is throttling (and perhaps not coming back from a throttle, though I've never heard of that), that would account for it.  

Get a program that records the history of the temp, like MSI Afterburner or, if you're using Linux, just write a quick script to to aticonfig --odgc --adapter=all every 30 seconds or so and append it to a file and see if your temps rise too much at one point.

But seriously, what you describe is exactly what I see on my bank of 5870's if they are overheating, except they come back from throttle, but I am using a custom BIOS on all of them, so I don't know what your BIOS is telling the card to do.

It could be that your BIOS is set to throttle at a much lower temperature than other BIOS.  Mine throttles the card at 90C.

[ensign_lee]

Update:

I think I figured it out!

What I didn't realize after installing my two 5870s is that they would each also take up a core on my CPU when run not crossfired.

I'm also running SETI@home on my CPU at 100%, giving it all 4 cores on my i5-2500k.

So SETI and poclbm were fighting for the same resources on 2 of my cores, thus resulting in lower activity on the poclbm.



P.S. To answer previous questions, one monitor plugged into each video card. And I don't think cards overheat at 75 celcius. I thought they start overheating at 90-100

[Muhahahahaz]

Windows

This is most likely your problem...

Seriously... in Windows, my hash rate varies wildly, but Linux is rock-solid.