Unable to OC my MSI 6950 Twin Frozr III Power Edition - no matter what !!

[ze_undertaker]

Hi - I recently bought a MSI TF III 6950 PE and I wanted to squeeze as much as I can out of it.
Why such an old card, well it's simple - I do a lot of Sony Vegas editing and the 6 series is the last to be fully supported by the Main Concept codec and I do need that huge speed gain from using GPU when encoding.

Anyway - back to the TF III card ... first I tried unlocking the shaders with the MSI Custom bios - but they are locked ( no surprises there ) to 1408. I said hey at least I was able to unlock my OC settings in After Burner with this BIOS and figured I could squeeze a bit of extra performance there. However I can't seem to be able to get past 870 Mhz on core clock because everything becomes unstable and Furmark crashes in 5 sec. I need to state that I successfully unlocked the voltage settings in the Afterburner by editing the cfg file so I can input anything I want. Also the core and mem clocks are "unlocked" so theoretically I can go as high as 1300mhz ( core ) and 1690mhz on memory ( I think ). So everything is as it should.

Now, what I am interested in is the core freq more than the memory so I tried upping the core voltage to 1.170V, 1.2V, 1.25V, even 1.3V with the power limit to 20% everytime ( left memory at 1300 ) - as a side note - this cards default clocks are 850/1300 as it's an OC edition. When trying to hit 900 mhz I get Furmark to crash in only a few seconds ( even at 880mhz ) - no matter what voltage I try. The temps are okish - in the 70+ mark. With stock clocks I can run FurMark with no problems and the temps don't get higher than 75 so I don't think its a temp issue as when overclocked, it doesn't even hit 70 and it crashes. My PSU is a Corsair 750W so I doubt that's the issue. I also have a plus "power meter" and when running FurMark @ stock I get about 302W power consumption and about 312W when trying to overclock for those few seconds that FurMark actually runs.

I know each card is different, but I've seen these all over the internet to hit 1.000+ mhz with no issues, but I can't even hit 900.

WTF am I doing wrong ?

 

[coozie7]

Mine was the same, a first gen card it did unlock, both shaders and to full 6970 specs.
But it would fall over at the tiniest attempt at overclocking, stock or flashed, looks like you've just been unlucky with the silicon lottery, mate.

 

[maddogfargo]

Some 6950's can be flashed to 6970. this will usually increase voltage, speed and shaders.

Unfortunately, it sounds like the newer models of your card will not unlock shaders.

But the good news is it sounds like they can at least be flashed to improve overclocking results.

http://www.techpowerup.com/forums/threads/msi-r6950-twin-frozr-iii-flashing.150793/

 

[ze_undertaker]

Mine could be a 07/2011 built according to the sticker.

Anyway as I said, the Shaders didn't unlock but only a few cards actually did so no problem there.
However, with this custom Bios MSI released I should at least be able to pull some nice clocks out of it... because pretty much EVERY CARD can be overclocked but I only managed 20mhz on the core and that's just crap, especially on this TF III 6950 model which is considered among the best overclockable and stable versions.

 

[vonss]

Hello, I'm currently having the EXACT same problem with the same GPU.
I manage to discover that part of the issue is that when you incrase the voltage on MSI AF it does not really increases it (I checked with AIDA64/HWMONITOR/HWINFO/OHM) is "stuck" at 1.150v.