How memory clock relates to engine clock?

[durbs]

Hi, i'm not really into overclocking but have recently built a 2600K rig with a 6950. Overclocking the CPU was fine as I just used the Asus o/c utility which sets it to 4.4.

Not sure on the GPU though? If you look at the screen from the supplied SmartDoctor app below, i've raised it from 810 MHz to 833 MHz and it seems happy with that and my 3D Mark 11 score went from 5128 to 5237 so its obviously done somthing good.

Memory clock though, dont know what to do? I raised it 'some' from 5000 to 5044 but does it need to be in line with, or some multiplier of the engine speed?



Also, anyone know what vague numbers I can safely aim for?

Ta.

 

[Operation]

Can't answer your main question, but 900MHz is not an unreasonable target. I have my reference model running at 877 MHz and probably have a bit of headroom. This is without touching voltages.

 

[Marine-RX179]

To be honest, core clock has a much high impact on increasing frame rate than memory clock, so you should really focus on pushing you core clock to as high as possible first, before playing with the memory clock (otherwise if your overclock is unstable and crash, you wouldn't know whether it is the overclock on the core or the memory that causes the crash).

Most 6950 core clock would clock to at least 880~900MHz, good ones would do up to 950MHz, and some very good ones would be touching close to 1GHz. It's depending on how good is the GPU chip that's randomly picked for your particular card. Also, remember high overclock require increase voltage for keeping the overclock stable.

 

[robbieshanks]

Worth doing a bit of google research though. I recently read that the 6850 will give you much more improvement from overclocking memory than GPU. Something to do with it being memory bandwidth limited rather than processing power limited. Don't know if the 6950 is the same though.

I think it sounds like you can afford to push on with overclocking your GPU a good bit further anyway. Usually best to overclock just your GPU until you get a stable, satisfactory overclock and then start working up the memory clock speed - benchmarking to make sure it is still increasing your frame rates. Pushing memory too hard has been known to reduce framerates occasionally...

 

[durbs]

Thanks folks, wasn't sure whether they needed doing together but sounds like thats not the case so i'll have a play with the core clock speed to see what i can get. Looking at the numbers above, seems I can push it a fair way yet.