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Title: Unstable hashrate 7970's - goes up and down Post by: Spetznaaz on May 09, 2013, 07:14:03 PM Hi, i was wondering if someone may be able to help me.
The hashrate on one of my 7970's is stable (GPU 0) without a monitor, but the other goes up and down a lot (GPU 1), and when i switch the monitor over to GPU 0, it becomes unstable a bit, but not as much as GPU 1 and GPU 1 is still unstable without a monitor just slightly less... - i fixed it once just by increasing voltage, but it seems to be happening again. Anyone know what it may be? Title: Re: Unstable hashrate 7970's - goes up and down Post by: AzureEngineer on May 09, 2013, 07:22:15 PM You're probably using high intensity on the GPU that is outputting to your monitor. An idle desktop can still take up a noticeable amount of processing power and thus your hash rate will fluctuate. Lower intensity can resolve it.
You can also use a program such as MSI Afterburner to monitor your clockspeeds. If you've overclocked the card too much with too little power, the clockspeed will not be stable. Title: Re: Unstable hashrate 7970's - goes up and down Post by: bobsmoke on May 09, 2013, 07:32:52 PM I have 1 7970 and after some testing it looks like the best intensity is 7 using cgminer.
Other than that I normally use 85% Fan and 1180Mhz Clock plus 1000Mhz Memory Title: Re: Unstable hashrate 7970's - goes up and down Post by: Spetznaaz on May 09, 2013, 07:45:59 PM Intensity 7 put me down to 17 Kh/s from 730Kh/s lol.
My current intensity is 13, 12 gives 420 Kh/s, both a lot lower than i'm getting with -I13 and the unstableness. As i say, when i swap the monitor over, GPU 1 hashrate is still unstable. It will go up to 730, then hang there for a bit then suddenly jump down to 660 etc.. But GPU 0 is completely stable when no monitor is plugged in to it. Title: Re: Unstable hashrate 7970's - goes up and down Post by: AzureEngineer on May 09, 2013, 08:25:22 PM That happens to just about all cards (in my experience). You'll have to run the card for at least five or so minutes to get a marginally accurate reading of hash rate.
Title: Re: Unstable hashrate 7970's - goes up and down Post by: Spetznaaz on May 09, 2013, 08:57:23 PM Hmm but the thing is, they are identical cards, and one of them is completely stable without monitor plugged in, the other is very unstable (varying by about 50-100 Kh/s) monitor plugged in or not..
Edit - No idea what i've done but i've been playing around with setting and now they are both stable at 710.. weird. |