I havea HD 7850 and it is overclocked to 1200mhz core and 5400mhz memory on 1190mv'si have seen a really good increase in performance on the card. I havent had a crash yet at 1200mhz, and if you do see crashing, just bump up the vltage a bit on your card, what cooler is your card fitted with? I personally fitted the arctic accelero twin turbo II on mine and its amazing, i max out at 52oC and my ambient is at 28oC usually. And it isnt even audible over my hyper 212
Im not exactly sure what cooler it has as I have not purchased an after market cooler yet so it has the stock one. I hear the 7870 runs pretty cool with stock though. Thanks this information does help give me an idea of what to expect as im pretty much a noob lol
I just picked up a second hand Sapphire HD 7870 and it seems to be overclocking a treat. Got it to 1240Mhz and 1450 memory and then took the voltage DOWN to 1.170 to try and keep temps down. Got a max temp of 80.