I do not want to overvolt my GTX 580 but I would like to squeeze some extra performance out of it by overclocking it slightly. What is considered a *safe* overclock for this card bearing in mind I have a Point of View model with default speeds of 772/1544/2004 MHz? At those speeds the card idles at around 30 C and rarely exceeds 75 C during gaming except for oddly Divinity II where it hits 83 C and never goes higher. Using MSI Afterburner I set the clock speeds to 825/1650/2050 MHz and tested it with the three Just Cause 2 benchmarks on max settings with 8xAA/16xAF at 1920x1200 (with includes the two exclusive NVIDIA settings too by the way). I understand this is a good test for stability. All three benchmarks ran fine as did the game when I briefly tested it. I saw no artifacts. Do you think that is a safe overclock for everyday game use or is it so low as to not be worthwhile?
I never found an NVIDIA card that can do below 10% GPU overclock at stock voltage. For the memory clock thought, I've seen everything starting from only 1-2% to as high as 25%. Anything that is REALLY stable and has the temperature under control (including PCB and power circuit temps) should be healhty for the card. Personally this is how I work: Start at about 8% GPU overclock with a temperature monitoring window (usually GPU-Z) and start a stress testing utility (usually ATItool). Every 2 minutes I start increasing the overclock 1 step, until I reach the GPU frequency that hangs/artifacts withing this 2-minute window. When I detect this, I immediatly stop the stress test and downclock the card to the previous value and I now start decreasing the overclock step-by-step until the value it completes the 1-hour stress test (usually it is only 1-3 steps below the previous frequency). If the card is for my mashine I select the maximum stable I find, but if I build it for someone else, I downclock it 2 more steps for more safety (actually the only problem is that if that frequency is not 100% stable 24/7, then whenever you detect some artifacts you must immediately stop gaming and decrease the overclock one step. If you just keep watching at them, they'll probably damage the card).
you know if you wanted a true safe overvolt you can go by the min .900-1.088 max vid. all 580`s should handle 1.088v no sweat. 850/1700/2200 is a decent oc and shouldnt stress anything on your video card.