just really want to know what's the best way to over-clock it and and what's a good temperature at the moment i have started to overclock it but only did it a little bit so any advice would be appreciated
I'd recommend MSI Afterburner, its free to download and very easy to use. I would start with either the core or the mem (rather than increasing both at the same time) and up speed by 10 or 15Mhz, test the overclock with a benchmark or game (I'd recommend Unigene Heaven V2.5)... If its stable after 10 minutes up the speed again.
You'll come to a point where you can't go any higher without causing instability, at that stage you have two options:
1)Decrease the Speed until you regain stability
2)Increase the voltage (MSI Afterburner only allows you to increase the Core voltage, I don't know how to increase the memory voltage without editing the BIOS)
Once you've settled on an overclock test it for a few hours and make sure the temps don't exceed 90C.
thanks for the help at the moment the gpu is set at 890Mhz and the memory clock is set at 1300Mhz while in game with oblivion on highest possible graphics it goes to about 70C tops with the fan running at about 60% might up the gpu by 10 more leave it at 900 though last time i did the auto test and that just ended up putting the card to high and broke so wasnt gonna do that again lol thanks again
One other thing to keep in mind is to test the actual performance of the card after OCing -- DDR5 memory is a bit different in that it incorporates some more error correction routines and will resend the info if it is corrupted (older memory would just display the error as artifacts on the screen where DDR5 will slow performance while it gets the errored info resent and corrected ) - So sometimes a slight increase in the clock speed of the memory will increase errors received and actually slow overall performance of the card due to the increased usage of the error correction - You would notice this on older cards as artifacting on the screen so could readjust the OC but with DDR5 it sometimes goes unnoticed and just slows performance so that a lower OC would actually result in better performance overall.
i will be getting a new one soon this is just for until i enough money then ill get the 6970 once ive read into it a bit do you know if thats any good?
The HD6970 is an awesome card, wel over double the performance of your current HD5770. Its worth looking out for a reference 2GB HD6950, they have a very high success rate of being flashed to a HD6970.