Defective Shaders Unlocking 6950 - Can I lock only the defective ones?

[Keavon]

It's my first time here, so hello everyone!

I've just decided that I wanted to finally unlock my Gigabyte Radeon HD 6950 2GB (GV-R69D5-2GB-B) that I got in April 2011.

I followed this guide http://www.techpowerup.com/articles/overclocking/vidcard/159 and it all worked great, except there were lots of colorful dots and screen skewing and other problems. Here are some images of the problems:

http://imageshack.us/photo/my-images/198/glitches.png/
http://imageshack.us/photo/my-images/252/streaks.png/
http://imageshack.us/photo/my-images/833/textwarp.png/

I believe that is caused by defective shaders, so I'd assume that I had a partially defective chip with 128 or less shaders not working, which made them put a 6950 BIOS on the chip, determining its fate in my hands as a 6950 owner.

So my question is if it's possible to modify the BIOS and disable only the shaders that are actually defective, so I can at least get a few more shaders for free.

If this is possible, how would I find which shaders are defective, and how would I disable only those?

Thanks.

 

[(sic)Klown12]

Not that I'm aware of. They're grouped together(look at a high level diagram from Cayman reviews to get a better idea) in such a way that you can't access individual "shaders". It's an all or nothing approach.

 

[hyrule4927]

I may be wrong, but I'm pretty sure there is not any means of selectively identifying and disabling individual defective shaders.

 

[max347]

Did you up the voltage? If not, that is why you have the artifacts on your screen

 

[Keavon]

Did you up the voltage? If not, that is why you have the artifacts on your screen

I upped the voltage to +20% now (and rebooted) but it's still having the same problems.

Any other recommendations, or was I simply unlucky?

 

[3DVagabond]

Did you flash it by flashing it with a 6970 BIOS? Or, did you do the 2nd method below?

Update 2: Above method is only for 2 GB HD 6950 reference design cards. If you have a custom design or 1 GB card, then use RBE to modify your existing BIOS. Save the BIOS from your card, load it into Radeon Bios Editor, enable the shader unlock option on the last tab, then flash that modified BIOS to the card instead of the one downloaded from this page.

Some 6950's exhibit memory issues when simply flashed with a 6970 BIOS.

 

[max347]

Its possible you were unlucky. But first- did you use the asus bios? It may be the overclock that is messing with it. I would not give up on it yet.

What are your core and memory clocks? Drop them to 6950 clocks (800/1250) and see if that alleviates the problem. No, you wouldn't have a full 6970 then, but still an improvement over a stock 6950.

I do have an unlocking 6950, just waiting for a new power supply before I can plug it back in. I'll see what clocks mine is running at when I install it

 

[Keavon]

Its possible you were unlucky. But first- did you use the asus bios? It may be the overclock that is messing with it. I would not give up on it yet.

What are your core and memory clocks? Drop them to 6950 clocks (800/1250) and see if that alleviates the problem. No, you wouldn't have a full 6970 then, but still an improvement over a stock 6950.

I do have an unlocking 6950, just waiting for a new power supply before I can plug it back in. I'll see what clocks mine is running at when I install it

I'm using the Saphire BIOS that the tutorial gives a link to in the unlocking steps. I lowered the memory to 1250, and rebooted, but still have the artifacts.

On a related note, I've used RBE to modify my stock BIOS that I ripped from my card, and clicked the checkbox to unlock the extra shaders. It also caused the artifacts.

 

[max347]

Alright well, if you've overvolted it and downclocked it, looks like you may have a bum card man, sorry :-(

 

[wiammaren]

I'm pretty sure there is not any means of selectively identifying and disabling individual defective shaders.