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I'm using MSI Afterburner to over clock my two Sapphire 5770 cards but I can't seem to get them stable above a core clock of 930MHz.  From what I've read on these forums I was expecting to get them higher.  What experience are others having with the 5770 card?

Thanks in advance.

Are you increasing the voltage on the cards or leaving it factory?

1.) i use trixx not afterburner
2.) i only run my 5770 at 950mhz for stability sake

You can push them to 1000mhz but in my experience that tends to make them unstable after a day or two on regular air cooling, liquid cooling will produce better results as far as that's concerned. a small voltage bump may be necessary to reach that speed and you're going to want to downlock your memory to 300-400mhz depending on what's stable for your particular card

Overclocking is a lottery. You can get lucky, or not.
930 Mhz is a decent overclock. Some cards can do more, some cant. Better cooling could help push a few % higher, but even thats not guaranteed. There is a reason they are sold as 850 MHz :)

My main 5770 I can put at 1000/300

Got another one in today, 960 at best, 940 is stable.

It's only a loss of ~15 mh/s.  Nothing major.

you can also use the new CGminer, set the fans/thermal setting to 50% / 80'c using --auto-fan/--auto-clock and it will move between 850-1000 / 300 depending on the temps you want to maintain or how good your cooling is. it will also handle GPU load/crashes, etc.

i've run 2x5770 with aoclbf at 950/300 and 850/300 in a regular case, no power tweaking was needed. but, i think using cgminer makes it way easier, as you can see more of what's happening as it's happening, and it handles soft-restarts of the GPU pretty well if you're trying to find temp/voltage limits and tolerances while under load.

I just want to say you need to be very careful when doing this!

I cant get mine above ~950Mhz unless I lower the mem clock to ~335Mhz. I bump the voltage up as well to ~1200. Im sitting at 1020 and 335 right now which is turning out 237MH/s

Be careful about overvolting.  AFAIK, the extra power consumption doesn't make up for the extra hashes. But of course your mileage may vary.

thanks for your nice sharing

If I kill the card it gives me a chance to convince my old lady to let me purchase another, hopefully higher-end card  :D

Hi, currently i have 1 rig with 4x5770.
Now on every 5770 i put one CM fan so temps are round 68-74C.

Currently clock is 950Mhz(gpu)/300Mhz(mem) with factory voltage.
I tried it on 1000Mhz 1050Mhz. GPU was stable but Wattage and Temps were so high so i cant see point to do it for 10MH/s per card. Now i stopped on 950/300 i guess its best OC for 5770.

Good Luck and watch Temperatures and Wattage.