Hi all,

I have been trying to overclock my ASUS Radeon HD 6950 DirectCU II 2GB however I have been unsuccessful. I have tried various tools to do this but none of them seem to let me overclock the voltage.

I am assuming it's the voltage I need to raise as when I get to around 880MHz my PC will power off and restart. (No blue screen). I have read that ASUS Smart Doctor can be used to control voltage however I have installed the latest version of this and it comes up as an error message saying that no card could be detected.

Any ideas on this?

Thanks

Hi and welcome.

Have you tried MSI Afterbuner?

Hi and I second the welcome.

Have you made sure to increase the Power Control slider in the Catalyst Control Centre?

+20% usually does the trick.

As you're overclocking the card is possibly going to need to be able to draw more power than the 0% setting allows.

Hello and thanks for the welcome.

Yes, I have tried MSI Afterburner but still come across the same problem even with the power control at +20%. It runs fine on 880MHz but it I try 890MHz it will run for around 30 seconds under load and then the PC will restart with no error messages being displayed.

Today I have tried overclocking by changing the BIOS settings, since it has dual BIOS i thought I would give this a go. I used RBE to change the settings and ATi Win Flash to flash the card. However again I ran into problems if I even increased the GPU clock by 10MHz from 810 (stock) to 820 and restarted the computer, I would then get a BSOD at the windows loading screen - System Service Expectation.

However I have successfully unlocked the shaders (to the 6970 shader count) and changed the fan profile using RBE.

My Power Supply is 750W, so I don't see a problem here.

I don't know where to go from this, maybe my card just does not want to be overclocked.

Could just be that particular cards limit as you say.

What PSU is it?

I wouldn't say that it is a known PSU - Oryxx Ultra 750W.
Even if the PSU was the problem, I don't see how I could get different results from overclocking using software or using the bios?

Maybe I should get a better or well known PSU but I haven't had any problems with this one yet.

Edit: I should mention that with overclocking software I can get to 880MHz but when overclocking via bios I can't do anything apart from unlock the additional shaders and change the fan profile, changing clocks by 10MHz from stock resulted in blue screen at boot, (obvisouly with software overclocking disabled)

After some searching I have noticed somebody else has had a similar problem and flashed their card with the ASUS DirectCU II Radeon HD 6970 2GB bios with no problems and it also allowed them to overclock a bit. So I shall give that a go if I can find the bios online. Fingers crossed.

Update: I can confirm that I have successfully flashed my card with the ASUS DirectCU II Radeon HD 6970 2GB bios - available here

Just completed a few benchmarks and all seems to be running great!

Happy days! i wish mine would flash. I have newer versions of the 6950. Wont unlock :/

That's a shame, have you overclocked yours at all?

Mine wasn't wanting to be overclocked at all as I'm sure you can see from my posts above so I was surprised this bios worked. Going to run in for a few days on the stock settings and see how it goes, under load at the minute I am getting temps of about 65-70.

Update: Cranked up the fans to 50% temps now between 60-65 under load and 40-45 idle.

Im running xfire with mine. I just got to max CCC limits, 840/1325. Thinking about installing AB again.

Very nice, what sort of temps you get with that?

top card idles at around 35c and bottom around 32c, under load in bf3 the top hits about 60c and the bottom around 55c. All with fans on auto.

InsaneAssass1n said:

Update: I can confirm that I have successfully flashed my card with the ASUS DirectCU II Radeon HD 6970 2GB bios - available here

Just completed a few benchmarks and all seems to be running great!

Click to expand...

You should only use the shader unlock bios, Risky running a 6970 bios as memory modules were different (maybe things have changed a year + on)Anyway one thing you didnt check was what the v-core was actually set to befoe you flashed your bios. I'm willing to bet that it was default at 1.10v a
and the new bios has it around 1.175v= default 6970.

Check gpu-z to see.

This was a screen shot half way through running Unigine's Heaven DX11 benchmark.


Screenshot by ceryt, on Flickr

The voltage seems to rise to 1.2, higher than what you expected. Do you think I could run into problems?

Only problem being with the shader unlock bios, I can not overclock it at all as it keeps causing my PC to restart. Although if this bios could potentially damage my card I think I would rather just stick with the stock bios and clocks with shaders unlocked.