Should I start with increasing the core clock or memory clock? Should I be concerned with one bottle necking the other? I tried the 860/1100 mhz that the factory overclocked version of my card is at, and it was a bit unstable (worked in furmark but crashed playing sc2).
I'm currently doing 870/1000 and so far its done a 20 minute furmark bechmark and a 10min sc2 game without any problems or temps above 56c. (Fan never went above 50% either )
Also, I haven't messed with the voltage (People say that's more likely to fry your card) but it came at 1.15v. Not sure what a default 6850 is set at.
Leave the voltage alone. I think it's a better idea to go for the core clock first, as that's more likely to be your bottleneck. The fan depends entirely on your preference and doesn't reflect on your card's OC-ability, as the default fan profile isn't any better than one you can make yourself. I recommend creating a fan profile that gets the speed to just below obviously audible at the highest temps you hit in your stress tests. That happens to be 57% for my 460, but you'll have to experiment. Have fun
I just mentioned the fan so people didn't tell me it was overheating....
Anyhow, I've been slowly increasing the core clock as you would expect, but if I do anything at all to the memory clock, it will usually go through a furmark benchmark, so I figure its at least fairly stable, and then my pc will crash not long after. Whats up with that? Why would the core clock overclock without a hitch but the memory clock can't be touched at all?