7950 - GPU usage jumps 99% -> 64% -> 99%

[teh-kontra]

Hello.

I am trying to optimize my MSI R7950 and I have an issue I cannot resolve. After 4-5 minutes of mining (cgminer 3.5.0) GPU usage starts to jump from 64% to 99% frequently, as seen on screenshot (also configuration). To be precise: it stays on 99%, goes 100% for a blink of an eye and falls to 64% for another few seconds. Then back to 99, 100 and falls.

Happens on intensity 18 and 19. Also on 17, but with less frequency. 16 and below are ok.
Intensity 20 crashes almost instantly. I can't figure out how to change voltage - whatever I do, it stays at 1250mV.

https://i.imgur.com/eaMBi0L.png

GPU clock also jumps in same moments. (eg. core: 1050 MHZ -> 501 -> 1050, memory: 1400 -> 1250 -> 1400)I tried many voltage and clock configs and it happens all the time.

I searched and found people with same issue, however their solution won't help - I already have powertune to 20% (both in afterburn and cgminer config).
https://bitcointalk.org/index.php?topic=167392.0
https://bitcointalk.org/index.php?topic=155842.0

Any ideas? I'd appreciate any help.

[Don007]

I also own a HD7950 (a Gigabite WF3) and my GPU is always about 95-100%, even with a low intensity (with mining Scrypt based altcoins).  I'm not sure what does cause that.

[teh-kontra]

Have you tried many configurations? What miner do you use? Could you please show mi your config? I have no idea where to start to solve this :/

[Cyberminer]

Is this the BE version of the card?

[Don007]

I'm using a stock GPU. Using the following commands: --thread-concurrency 21712 -I 18 -g 1 -w 256 --temp-target 76 --gpu-fan 25-80,65 --auto-fan --temp-overheat 82. 

[teh-kontra]

Is this the BE version of the card?

Yes.

I'm using a stock GPU. Using the following commands: --thread-concurrency 21712 -I 18 -g 1 -w 256 --temp-target 76 --gpu-fan 25-80,65 --auto-fan --temp-overheat 82. 

Thanks.