Overclocking unlocked 6950 (1536 shaders)

[Azarathal]

Heya guys, before I unlocked the extra shaders I was running at 880/1325 without touching the voltage, after unlocking at the same clocks I get artifacts and 10second lock ups.

Obviously I'm going to need a little more juice but what would your recommended voltage / clock speeds be? It's an MSI TFIII, I know the usual method is "see for yourself" but I'm just looking for your personal experiances.

Edit!
Stuck at 900/1325 as even unlocking MSI After burner throws up screen tearing / splitting and amd driver crashes. Got 900/1325 @ 1.125

 

[humbug]

Unlocking 6950 to 6970 shaders is not always as straight forward as ppl think.

The 6970 has a different PCB designed for those extra shaders.

6950 - x2 6 Pin Power line.
6970 - 1x 6pin + 1x 8 Pin.

The reference 6970 PCB's also have a higher grade Caps, and Memory IC's. custom PCB's is anyone's guess....

So there could be some compatibility issues there, as well as power delivery issues.

You could try turning the volts up to see if it stabilizes.

There is a question hanging over this whole 6950 to 6970 thing, the 6950 is NOT a 6970, it has a lesser PCB, it is a lesser GPU.

The question is will it burn out prematurely.

 

[Azarathal]

The way I unlocked it modified the original bios on the board to unlock the shaders only, other methods unlock the 6970 core/mem clocks and voltages which is why they burn out. I didn't really ask for any opinions on the matter but thanks for your input anyway.

 

[DarkHorizon472]

Just my experience with the same card. Unlocking the shaders did next to nothing in terms of performance so I just put the cards BIOS back to normal.

Normal over clocking works fine and I just run mine at 880 / 1325 on the default voltage (1.2v) which is completely stable maxed out in BF3 for a good few hours of play.

Don't forget to check what temp your card is running at as over heating will cause strange effects. Mine runs at about 60C maxed out for hours again on the default fan settings.

 

[Davedree]

shader unlock rarely gives you much boost if you still have 6950 clocks. 6970 4-10fps gains come mainly from the higher clocks.
The power delivery issues aren't that bad unless you were to run over 1.25v.
A ref 6970 uses 1.175, so you should try upping the voltage to around that it won't be a problem running that voltage, 1.125 is too low.

Have had mine unlocked since dec 2010, have used it at 940/ 1375 at 1.2v.
Theres room for more i've had it at 1ghz/1375 1.25 but it runs too hot for little gain in performance.

 

[Davedree]

Unlocking 6950 to 6970 shaders is not always as straight forward as ppl think.

The 6970 has a different PCB designed for those extra shaders.

6950 - x2 6 Pin Power line.
6970 - 1x 6pin + 1x 8 Pin.

The reference 6970 PCB's also have a higher grade Caps, and Memory IC's. custom PCB's is anyone's guess....

So there could be some compatibility issues there, as well as power delivery issues.

You could try turning the volts up to see if it stabilizes.

There is a question hanging over this whole 6950 to 6970 thing, the 6950 is NOT a 6970, it has a lesser PCB, it is a lesser GPU.

The question is will it burn out prematurely.

The burnout theory is more based upon the 6970 bios due to the memory timings and memory voltage.

 

[bru]

Has nobody thought that the reason some 6950's were 6950's and not 6970's is because they had faulty shaders, chips that didn't make the grade. Maybe that's why your chip won't unlock without artifacting and crashing everywhere.

 

[Azarathal]

Maybe you're right, it works perfectly though until I unlock msi after burners core+mem clocks, before I'd even changed any settings

 

[Nelly]

It's a waste of time really, best to just clock your core and memory as much as you can, and leave it at that. This was my findings on my Gigabyte 6950 2GB.