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Asus Direct CU II 6950 Overclocking and shader unlock

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Joined
2 Aug 2008
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50
Well guys i went with the Asus Direct 6950 CU II in the end from overclockers, it does have a switch, but im unsure whether the bios is unlockable, i haven't tried yet, for now i wanted to see just how far i can push it out of the box. I will look at the 6970 shader unlock soon if it can at all be done on this card. So far i have heard several different outcomes .Now are artifacts caused by low voltage? or by high clocks? and what is the highest recommended voltage i can take this to? I've scored 30k+ in 3d mark 06 and just a shade under 5900 in 3dmark 2011. Currently sat @ 1.26v and 965/1420... the temps are fine max.. around 63 but creeps up to 82 on gpu temp#3.

What's the maximum voltage i should try for say a 24/7, and then for a bench run?

I think 1.26v is high..


Thanks in advance.

Also if anyone has any experience of unlocking the shaders on this particular card, and i have seen the thread at the top of this sub forum... then please share with me..

Thanks :0)
 
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I assume your GPU core voltage isn't at 1.6V?

The standard voltage is, I believe, 1.100V so I'm sure 1.6V would fry the GPU.
 
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Have you set PowerTune to +20% in the CCC?

1.26V seems a little high. I've seen reviews where 950MHz was reached with 1.15V.

Increasing the core voltage doesn't increase the VRAM voltage. Perhaps 1420MHz on the VRAM is too much and causing the artifacts.

I'd suggest backing down on the VRAM speed and see how it looks then.
 
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ok fella done just that.. really some people getting that on 1.15? good grief..
benches fine in furmark and kombustor and ran 3dmark vatage fine too.. no artefcts, but if i drop the cvore it crashes... if the temps are fine am i ok to leave it as it is? still at 1.26
 
Looking through a few reviews suggests that 1.26V is at the upper limit of where you want to be.

For extended use it might be a good idea to back down on the voltage a touch and use whatever speed you can get with, say, 1.200V.

You're not going to notice the difference between 965MHz @ 1.260V and, say, 940 MHz at 1.200V but in the long term your GPU might appreciate the lower voltage.
 
From my experience oc'ing 6950>70 CrossFire, 1Ghz+/1400MHz on the memory @1.265v using AC extreme coolers.

If you put the voltage up, you really really need to keep your eye on the temps of not only the core, but the vrms also!

The memory is the stumbling block with 6950 oc'ing, if you drop the memory back down to 1250 and put the core up until it's unstable, then back off and then start oc'ing the memory, as surveyor mentioned you need the +20% in powertune also.

BUT be aware that there is a chance you can brick the card if you oc the memory too high from what I have read here and from other sources!

There really is diminishing returns going above 1GHz on the core, I only use these kind of speeds for benchmarking and found that 950MHz/1400MHz@ 1.1/75v(game dependant) is the sweet spot for me.

It's pretty good performance for me considering at those speeds it's in 580 Sli territory for the price, considering both unlocked 6950's cost me £50+ less than what 1 580 would have cost at the time.

Wow, just realised it's been almost a year since these cards have been out, really starting to get my moneys worth out of these bad boys now! :D
 
At the moment, i have dropped back down to 1.2v... at this voltage kombuster crashes at 950, so i have stepped it down to 940, and put the memory to 1375... seems to be absolutely fine now. :0)

Thanks guys for your help...

later on im going to see exactly what difference 1.175 to 1.2v is and may take a further step back to compensate... i suppose if i want more the shader unlock is the way to go.. as i have a switch on my card does that mean its a switch able bios?

regards

:cool:
 
This card only has one bios, the switch on the side converts of of the dual link dvi outputs to single link and enables another displayport output (check the box/manual). I think some people have successfully flashed it to unlock shaders but obviously it is slightly more risky than dual bios cards.
 
but in theory doesn't that still make it a bios switch?,
as in one setting for single and one for dual, done in the bios itself?, or does it just amend that one thing in the same bios?
 
Regardless of whether it's a dual bios or not, be careful if you are going to be flashing it!

Do you really want the hassles or have onboard gfx/2 pci-e slots and spare gpu while maybe having to attempt a blind flash if you have too?
 
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