HD5770 overclock problem

[vertical777]

hi, I have 2 asus HD 5770's in crossfire and I'm having a problem overclocking them, it seems that whenever I up the clocks to above 920/1250 my computer crashes when playing games. I've read that these cards overclock like monsters even with stock voltages, but my cards seem to say otherwise.

Also, I'm having a flickering problem, It's very obvious when I run furmark, it looks like horizontal lines passing through the screen making text/textures disappear and reappear rapidly. forcing vsync in CCC seems to suppress the problem, but I can still see it.

I'm fine with the vsync problem but I'm hoping to get more out of my cards with overclocking. I hope you guys could help. thanks.

 

[vertical777]

is it possible that this is a driver issue? I cleaned the drivers with driversweeper before installing new ones.

 

[szymek]

It's not a drivers issue, your card is simply oced too high and what you have to do is pump up the voltage or downclock a bit. To overclock you may use MSI Afterburner (it can raise your voltage either) and to check stability FurMark or if you prefer OCCT. And do not forget to check the cards temperatures. Furmark can really stress gpus. Good luck!

 

[CrysisComa]

1+^ also keep in mind that crossfire really raises the temps already giving you less temperature headroom to overclock