Overclocking the 5770

[maestr0]

I've reached a stable OC at 1000 core /1351 memory at 1200mV, but now I want to push this card even further. It plays Crysis nicely (well, all levels but the final battle) with an average of 20fps, but the final battle against the alien battleship-looking thing I maxed out at 3fps. I know I'm not going to get much more out of this card, but I want to try. I've found that independently, I can get a stable core at 1045MHz at 1287mV and a stable memory at 1410MHz at 1287mV, but when I put the two together, the overclock is amazingly unstable. I get a maximum of 2 seconds out of Crysis before the system locks up or the screen is filled with bars. My only guess would be a power limitation somewhere, either an insufficient PSU (mine's 700W) or a driver limit. I clocked that down to 1045/1375 to compare, and at these speeds I get artifacts. I tried at 1300mV, and there are fewer artifacts, but they are still there. My concern is raising the voltage too high - I have a custom fan profile that keeps the card under 70 degrees celsius, but I don't want to burn it. Also, Ive noticed my memory speeds are unusually low compared to many overclocks I've seen, and in contrast the clock is unusually high. I plan on replacing this card soon (with a GTX 580 or maybe a 590 ) but don't want to break it before I receive a new card. Is it worth upping the voltage, or should I begin reducing the core clock until the artifacts disappear?

 

EDIT: I've also just noticed a high-pitched sound emanating from the card - should I be concerned? It gets screechier the harder I stress it.

Edited March 27, 2011 by maestr0

[overclocking101]

the cards have overcurrent control. you can disable it but it is a hard mod and not suggested unless you are real good at it. the 1ghz and 1351 mem is a damn good oc for those cards. i'd say grab a second or a better gpu

[maestr0]

Well, after a little more trial-and-error, I seem to have gotten it stable at 1020/1360 at 1299mV. However, this produces temperatures up to 77 degrees celsius. Oh well... Air isn't perfect.

[Speedway]

EDIT: I've also just noticed a high-pitched sound emanating from the card - should I be concerned? It gets screechier the harder I stress it.

 

I assume when the temps on your cards get high enough that the fan is running at 100% to keep your temps as low as possible? If so, then the high-pitched sound could be your fan starting to go out. I had the same issue on my 5970, and it was the fan. When it comes to gpu's, if you run the fan at high rpm's for extended periods of time, you will shorten the gpu fan life! But, like you I use customized fan profiles through MSI Afterburner, and when the temps get to a certain point, my fan kicks into high gear to combat the rising temps.

[dihartnell]

I would stick with the 1000 core /1351 memory at 1200mV. Thats a damn good overclock already and the extra 20MHz on the core and 9MHz on the RAM isn't worth the additional stress you are putting on it.

 

If the card isn't up to what you want with that sort of overclock, then you have the wrong card. Either get another one as suggested or get a higher performing card.