Need OC advice - HD 7950

Hello -

I just got a VTX3D HD 7950 OC X-Edition GPU.

Stock Settings:
Core - 925 MHz
Mem - 1250 MHz
Volt - 1250

I am new to overclocking and have been reading forums and guides to figure out how to do it. I've been using Sapphire's TRIXX and benchmarking with FurMark (1080 preset; Anti-Aliasing off).

I am very confused and hopefully someone could explain this to me. After an hour of trial and error, here are my results:

I get a consistent 46-47 fps average and a FurMark score of 2775. But the confusing part is I get this same score with a really crazy range and combination of settings...

core: 925 to 1250
mem: 1000 to 1750
power: 13% to 20%

I have not changed stock voltage. Temperatures range from 78-82*C (but ambient is quite high in the room).

So basically what I've concluded is that my maximum fps (at this voltage) is achieved basically only by raising the board power above 13% and is not affected by changes in core/mem MHz.

Could someone explain this to me?

Other relevant info:

CPU: i5-2320 @ 3.00GHz
MOBO: Asus P8H77-V LE
OS: Win 7 64-bit
(I also have a generic 800W psu that needs upgraded to a reputable brand)
8 answers Last reply
More about need advice 7950
  1. I never saw much of a difference when OCing my old 7870. But on my gtx 660 I see 20+ fps difference with OC while gaming with fraps.
  2. Well my base benchmark at stock settings was around 37 fps, so that +10 fps after the 13-20% power tweak is an increase of over 25%. Not bad for an overclock at stock voltage. But I'm still confused about the settings and why I can't break that fps ceiling with all those settings cranked up. Maybe it's the CPU?
  3. Memory overclocking actually gets to a point where it degrades performance.
  4. Yeah I read that somewhere so I dropped it back below even the stock values and there was no change.
  5. Anyone? I think it's the CPU but that's really only a guess.
  6. In the end you still have the same GPU, shader count, ect that you had before your OC. Just something you can't change with an OC.
  7. Your fps doesn't increase with such an overclock?
  8. I was right. The fps bottleneck is caused by my older CPU. I stopped using FurMark and compared scores on 3DMark 11 instead. I saw that my scores were the same as others with the CPU and OC but that i was really low compared to someone who had the same (or less) OC with, say, a 3570k. So it's definitely the CPU.
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