Core undervolting/overvolting on multi HD 6950 setup

[e21]

I have read threads that discussed this topic on HD 6950 series in particular, however this issue is still persisting for me no matter what I try.

I have a rig running four shader-unlocked HD 6950s, on Windows 7 64bit, 11.12 Drivers with 2.5 SDK. Using ATI tray tools, I am able to adjust the voltage on HD6950 #0 and #1, however #2 and #3 remain at stock voltage (1.175 for my BIOS).

I have MSI afterburner 2.2 Beta 12 installed, with the EULA entered into the config, unofficial overclocking 1 (also tried 2), further up the config file, unlonlockvoltagecontrol=1 and unlockvoltagemonitoring=1 too; after I launch the app, I go into setting and also check unlock voltage monitoring and control there (just doing it in the config file does not change it in settings, nor does changing it in settings change it in the config). No voltage control for any HD 6950... nor do I even get to see the voltage...

Tried Sapphire TriXX, cannot even use the slider for voltage, it is locked.

Tried Radeon BIOS editor, and changing only the voltage of high performance profile to 1.1 (still higher than the other 3 profiles), I did not change any clock settings or anything else in RBE, saved BIOS and flashed it to one of my four cards; BSOD at boot, every time, every card.

I am able to run 920MHz at 1.075v, or 935MHz at 1.175, MH/s gain from 15MHz is not worth the power usage, or heat increase at 1.175v.

Does anyone have any tricks or tools that I have not already tried? Any help is appreciated, I will offer a couple BTC reward to anyone who can solve this.

[1715288048]

1715288048

[malevolent]

You can still try:

ati tray tools
barelyclocked

same tools as previously but on different drivers
I was unable to change voltage on my 5850s until I updated my drivers

[e21]

You can still try:

ati tray tools
barelyclocked

same tools as previously but on different drivers
I was unable to change voltage on my 5850s until I updated my drivers

I have tried ATT, which does work, but only on 2 of my 4 GPUs.
I have never heard of barelyclocked, but look forward to giving it a shot; I will gladly send you a couple BTC if this works.

[_Vince_]

I had too many problems with my 6950 and Windows, in the end I installed Ubuntu and flashed the card with new clock settings and voltage levels

Now my headless machines run on a usb flash drive and require no attention from me; even when in case of power outage, when the power comes back they automatically boot themselves and start mining

[malevolent]

I have tried ATT, which does work, but only on 2 of my 4 GPUs.
I have never heard of barelyclocked, but look forward to giving it a shot; I will gladly send you a couple BTC if this works.

Did it work? 
Barelyclocked is a tool developed by a forum member so it isn't popular outside of here, he doesn't visit the forums any more but it worked on all of my cards so far (5830, 5850, 5870 and 6770)
https://bitcointalk.org/index.php?topic=16406.0

alternatively you could also try AOCLBF
https://bitcointalk.org/index.php?topic=10264.0

[e21]

I have tried ATT, which does work, but only on 2 of my 4 GPUs.
I have never heard of barelyclocked, but look forward to giving it a shot; I will gladly send you a couple BTC if this works.

Did it work? 
Barelyclocked is a tool developed by a forum member so it isn't popular outside of here, he doesn't visit the forums any more but it worked on all of my cards so far (5830, 5850, 5870 and 6770)
https://bitcointalk.org/index.php?topic=16406.0

alternatively you could also try AOCLBF
https://bitcointalk.org/index.php?topic=10264.0

Barelyclocked did not work, it changed the core, but neither the memory clock or the vcore. I'll try AOCLBF and see if that works any better.

[sunbreak]

Which specific model of 6950 are we talking about here. I've had no problems with my 6950's so I'm interested.