HD 7970 OC Limits on Watercooling?

[earwicker7]

I've just started overclocking my pair of HD7970s. I'm already at 1155 MHz, which is 230 MHz over stock, and it's barely even breaking a sweat (1075 mV and low 40s temps on water).

What kind of numbers are people looking at on water?

 

[Sean W.]

man you can push those things like crazy. a single 7970 with a heafty overclock can beat a 6990/590.

the highest ive seen is 1250/1900...

ramp them up a step, stress test with furmark/a intensive game, if it passes raise the clock speed. rinse and repeat, until you get artifacts, then raise the voltage, stress test, if it passes raise it another step, stress test, and pump up the voltage... it could take up to 4-5 hours to find the perfect balance between stability, performance and heat.

but remember, you are working with 2 cards, its almost 100% guaranteed that you wont get as high of clocks with 2 cards as you could with one card... just the way it is.

or you could do what i do and go to 1.5v and put the clock speed all the way up and hope it sticks...

 

[PP Mguire]

Aren't these limited by the actual programs themselves?

Also, I don't know about AMD cards, but on Nvidia 1075 is pretty high even for water.

Edit: Let me know how far you get eventually. If I grab a 7950 I will be putting it under water and make it wish I was never it's master. On air a 7950/70 is looking around 1015 topping only with heat. If you are running that cool I'm sure it'll just keep going long as it can provide the voltage.