About a month ago i bought a MSI Radeon Hd 7770 graphics card for my budget computer build. It works great but i thought i wouldn't be using it to its fullest if i didnt OC the card with its capabilities. I then decided to try the overclocking program that came with the graphics card, the msi after burner. When i attempted to slowly add more MHz to its core clock and memory clock, it seemed to become extremely unstable. Right now the best i can overclock it to is only about 20 MHz above its normal core and memory clock. It seems others are able to push their core clock to atleast 1150, while i cant go any further than 1025 without risking constant crashes. My PSU is 600W btw, and i have the latest drivers from the MSI website. At peak performance my card also gets to 55 degrees Celsius, which shouldn't be a problem. Any one have any ideas on why my card seems to be so unstable?
Overclocking is very much the luck of the draw. There is no guarantee that you will be able to achieve 1150MHz on the stock voltage. Some cards can clock pretty high before you need to bump up the voltage to maintain stability. Other cards can barely get anywhere above stock clocks before they start crashing. You have one of the latter.
If you want to push further than 1025MHz, you'll have to increase your voltage. You have to do this at very small increments, and only just enough to get you stable at a desired overclock. Pushing the voltage too high will fry your card, so be sure to look up the maximum voltage spec for your particular card before trying to push it.
OCing GPU's is like everything else, some people can OC higher than others it just depends on your particular card. I used to make Android ROM's and people, using the same phone as me, would ask me all the time why they could only OC from the 600MHz stock to only like 680MHz before crashing when I could take mine up to like 826MHz. It's just luck of the draw.