The 7970 is incredibly efficient when undervolted but cranking up the voltage does almost nothing for clock speeds and power usage skyrockets. This is due a fundamental physics phenomenon which is related to the way we design transistors and the shrinkage of distance between source and drain called subthreshold leakage.
On a more practical note: My pair of 7970s can hit 1125 MHz at stock volts and generate about 1350 MHash/s.
Topic: OC 7970 (Read 1651 times)
Your right. I just wanted to see what it could do. I have it running 1100 no volts. I might put a little extra volts for 1150.
Just like my 5830's I had a few hundred hours at top speed on my 7970 at a glorious 1200MHz core. Ran a few more weeks at 1175, now I'm down to 1150. It's the crashes in the middle of the night that I don't catch until I wake up that kills the profits. Which means it's better to run at a lower core that is more stable than try to eek out that last 5MH/s. As far as voltage, every time I cranked up voltage I had diminishing returns on clock speed while power usage and heat skyrocketed. I don't recommend touching the voltage.
Now running 1125 core 670 hash. Gonna try for 700.
I have seen 689 out of mine before... everything maxed out. (1125/1375)
Good luck on the 700
DiabloMiner Rocks!
Was running 1200 core 720 hash.
Now running 1125 core 670 hash. Gonna try for 700.
Darn i thought i was done with these third party OC tools when i started using CGminer. Thanks for the tip will check out afterburner again.
use afterburner.
Lowest I've gotten mine is .949v ~ 1000mhz w/ 710mhz memory ~ 580mhash/s
Voltage won't change in cgminer. It's bugged. Use Gpu-z to verify the voltage. Also read the asic quality of your 7970's, as that will guide you with overclocking
Lowest I've gotten mine is .949v ~ 1000mhz w/ 710mhz memory ~ 580mhash/s
Voltage won't change in cgminer. It's bugged. Use Gpu-z to verify the voltage. Also read the asic quality of your 7970's, as that will guide you with overclocking
I just got a few 7970 to play with. Im getting 640 hash but i cant get core stable past 1080. Cant drop memory below 900. And im not sure if CGminer or trixx is controlling memory and volts. When i adjust with trixx it shows changes within trixx but not within CGminer. Who here has already played with these and can give me some tips? I hear people talking 1150-1200 core and 700 hash. I would like to get that too if possible.
Jump to: