CF 7950 overclocking advice

[Chrisoldinho]

Hi all,

I have been playing around with overclocking my 2 HIS 7950 IceQ Turbo's. Overall 2 really good cards, and I am trying to squeeze a little more out of them.

I am happy with the core speeds and voltage on both cards at, I am running 1125 @ 1.137mV, I haven't tested each independently here, but as it's only a 0.012 rise in core mV from the stock voltage I am quite happy.

However when it comes to the memory I have two very different cards. GPU1 won't go past 1350mV, I can get it to 1400 (just) if I back the core overclock right back down to stock, and run 1680 mV on the memory (quite a big rise for not much gain) but clearly it's not great!
On the other hand GPU2 is good for a minimum of 1525, I could have probably pushed it further, but I know at 1575 it fails at stock volts, probably with some tweaking on the memory voltage I could get near this.

I'm looking for some advice on how to best proceed, and there might be no solution here but the few questions I have are:-

Is it OK to run 2 cards at different memory clock speeds and is there any benefit to doing this (i.e. does it lock to core/memory the slower speed card)?

Would switching the cards around make any difference?

Can anything else be done?

Temps don't seem bad, I hit mid-high 70's on GPU1, and GPU2 barely hits 70, ever.

Thanks for the input,
Chris.

 

[se_vietboi]

Example, overclocking memory from stock to 1575 won't even yield much of an FPS increase in any game, usually 1-3 ish so if it were me I'd just leave them both on 1350.

 

[Chrisoldinho]

Thanks for this, I assumed the gains would be higher.

 

[se_vietboi]

Np its the core that significantly improves performance =]

 

[chris-82]

I also would have thought it would have given better results surely you have to oc the memory to a decent speed to handle the oc'd core's new clock speed.

 

[se_vietboi]

To my understanding, whether the memory is high or not, it won't have an impact on the core's OC. Like if the memory is at 1500 and you OC the core by 400Mhz, you might get 20 more fps. Now if the memory is at 1000 and you OC the core by 400Mhz still, you'd still get 20 extra fps.

Look around and you'll find similar responses. Or you can benchmark and see for yourself =] Oc'ing the memory is barely worth it.

 

[chris-82]

Interesting thanks for the info may drop my men clocks down to reduce vrm temps if that's the case (only 73c vrm).

Will have a little read on this cheers.