GPU overclocking problems

[crazysteve240]

I am trying to overclock a Sapphire HD 7870, my target increase in speed is 1165MHz on the core, and 1300MHz on the memory (I am willing to take suggestions on target speeds). That is from base speeds of 1050MHz on the core and 1250MHz on the memory. Whenever I launch a game, after about 5 minutes the GPU downclocks automatically to 150MHz for both the memory and the core. I think the max temp. I've seen with the overclock is 65-70 degrees celsius on synthetic workloads (e.g., Unigine Heaven) but it usually stays around 65 in games. Is there any way to increase the temp. limit because there is no option for that in MSI Afterburner or AMD OverDrive and I think that might be what is causing the problem. Also, increasing the core voltage is grayed out for me and I think that is also limiting me from pushing this GPU hard, I am fine with it running at 80 to 85 degrees celsius in games.

[WkdPaul]

For the voltage, you have to go in the Settings and enable "unlock voltage control"

[crazysteve240]

1 minute ago, wkdpaul said:

For the voltage, you have to go in the Settings and enable "unlock voltage control"

I did that, but the slider stays grayed out.

[WkdPaul]

odd, on my 7870 that's all it took!

 

If you can't unlock the voltage control then there isn't much you can do about the voltage.

 

For the OC, you can try a smaller OC, on mine the memory is easier to OC than the core.

[crazysteve240]

5 minutes ago, wkdpaul said:

odd, on my 7870 that's all it took!

 

If you can't unlock the voltage control then there isn't much you can do about the voltage.

 

For the OC, you can try a smaller OC, on mine the memory is easier to OC than the core.

What overclock did you get with both the memory and the core?

[WkdPaul]

I'm not home but if I remember right I got 1250 core (from 1100) and 1425 VRAM (from 1250)

 

EDIT : and I had vcore setting up, but that I don't remember!