I have an ASUS - GTX 580 DirectCUII and I've been interested in overclocking for some time so I am doing so preliminary testing.
According to MSI Afterburner my GPU (at stock) stats are as follows;
0% GPU Usage
13% Fan Speed
31C GPU temp
Therefore, I opened up Kombustor set resolution to 1920x1080, 3D API = D3D11, AA off and choose 'GPU Burn In', not the Extreme version. I tried the Extreme version before, but I left my fan on Auto so it was maxed at 30% and I got a BSOD after 10-12 mins. It did say that the setting could cause instability
I ran Kombuster for 20mins with fan speed set to 50% and my GPU (at stock) stats are;
99% GPU Usage
50% Fan Speed
64C GPU Temp (constant for past 15 mins according to graph)
There have been no artifacts or strange lines, is my card bad for having 64C already before overclock? I have not much room for overclock if I cannot exceed 80C.
GPUs are different than CPUs. You can push a GPU safely past 80c when under heavy load. How far past? Well gotta keep testing til you find that point. But 65c under load at stock speeds is well within boundaries to try and OC.
So I've ran Kombuster GPU Burn in @ 860 for 10mins and no artifacts and my temp remained at 65C for the last 6 mins so was not steadily increasing. I think I will increase my core clock again to 880 and 900 and see if any artifacts will show because I don't think temps will be my issue with overclock.
Might be a little quicker to research what people have gotten with your vid card. Its quicker and theres a lot less danger involved in overclocking a vid card rather than a CPU. You are however, doing it the right way. I read that people were constantly getting 1125/1575 on the 7970 without voltage tweaks, I tried it for my first OC and it works flawlessly. So I cheated a bit
920 @ 1.025v (stock) would instantly crash my card.
So increased voltage to 1.075 from to 1.025. This is a small increase and apparently very safe. I think the max is around 1.300
@ 930 - Did this for 10 mins and no artefacts. I have a constant 63C @ 54% fan speed.
I can't believe how good my card is lol
I tried 940 but crashed and but didn't crash if I increased voltage to 1.100 (another 0.025). However the temps ramp up to 73C. I don't think I should push my luck further although I could probably hit close to 1000mhz with the le way I have.