ATI XFX 5770 CF overclocking
I have two xfx 5770's in crossfire and i was wondering if i should overclock them and would it make much a difference in terms of performance in gaming? I have never OC before but i understand the basics. I have MSI afterburner but im scared to up the settings. right now they are sitting at 850/1200. if i bump it to lets say 930/1300 or higher would i have to turn the voltage up and to what? 1200? Also how will i be able to tell if after OC the cards, its hurting my computer or its not stable? is there a way to tell? it would be nice if someone can help me out with a good OC without hurting the cards or my computer.
overclocking will always improve your performance
when you overclock dont bump the speed from 850 core to 930 core but go in small segments, 10 or 20mhz and play a game. see how the computer behaves. there will be a point when the image will start becoming corrupt. this is when you know the overclock is not stable, simply back off 10 or 20 mhz
do the same with memory
start with core, small bump in frequency
test in game
once you got max stable core move to your shaders/memory
watch out for temps. i got my two gtx 280 oced running at 75-80 fan speed when im gaming
im still having a hard time understanding how i can tell if moving the numbers up are not stable.
i just put it to 875/1300
should i bump the fan up its set on auto on msi afterburner on 39%
update: while gaming my gpu1 temp is 70-71 on full load, and gpu2 is around 61-63 range on full load. Both my fan speeds are at 45%.
Should i up the fan speed or are these temps safe?
You can try using the ati tray tool utility. It has an option to scan for graphical artifacts. It is kind of stress testing for the gpu. On stock clocks, there would be on problems or artifacts. If you overclock your gfx card, the test will show yellow artifacts if the overclocking goes wrong. Run the test for at least five minutes to be sure your oc is stable. Run some games you like and look out for screen flickering or stuttering. If there is none, then your oc is good. About temperature, anything below the 80 degree cel is ok and most gfx card is perfectly ok on these temps.