I have HD 5770 and i overclocked it to 935c, 1375m from default 850c, 1200m.
1)If i set on 100% fan speed then while playing the most graphics intense game like crysis 2, most of the time it stays 77°C sometimes it goes 79°C max so is it safe or i shouldn't OC my gpu?
2)Is that ok to set 100% fan speed
i have this GPU which doesn't seems to cool memory clock:
For that, card, yes, your temps are expected. I would reccomend, slowly testing a lower clocks, until you get somewhere around 70c temps at the highest. Bring the memory down first, by 50mhz at a time, and test. Also, auto fan control sucks...they rarely go above 60% on it's own. I would use manual control.