How to undervolt 7950 vapor-x OC on linux

[jhk753]

Hi everyone,

I just finished to configure a 3x 7950 sapphire vapor-x OC edition.
It runs very well at 1920kh/s on xubuntu and it takes 800watt from the wall.

But I want to improve the energy efficiency.

First I have auto-fan with a target temp at 75C on CGminer.
Second, I try to undervolt with CGminer, but the command doesn't change the voltage.

Current config : Engine: 1080 Mem: 1500 volt: 1.15

I read a few things on how to undervolt vapor-x on windows, but does someone know how to do it on xubuntu ?

Thanks a lot.

[1715430143]

1715430143

[SkyNet]

Well if you cannot do it with the cgminer switches (--gpu-vddc) most probably you are out of luck. Also try another driver version.
If both don't work Windows is the way to go. Afterburner and Trixx will do it.
I don't think that you can undervolt a lot though with your current config (most probably 1.10)

[jhk753]

Ok thanks

[philips]

BIOS flash.

[micitzu]

Hi,

Bios flash? I am using Sapphire VaporX 11196-09-40G and there is only 1 available bios for this GPU V49_V4A.

Have you a modified version of the bios? I how that for the Gigabyte there is the F43 that is working very good.

Have you installed the Gigabyte bios on the Sapphire card?

At the moment I haven't been able to modifie the voltage on this cards (Trixx, Afterburner in win and amdOveridervoltage in xubuntu/ubuntu).  If I go on a high level configuration it goes to 1.250V, even if from the various topics it uses only 1.115 or 1.150...

I am not energy efficient at the moment...

Looking forword to your imput

I have tried:

win 7 - 64 biti:
- driver 12.8 / 13.1 / 13.4 (and all the available betas from 12.8 up)
- SDK form 2.4 up

xubuntu/ubuntu: 12.10 and 13.4 systems
the same drivers...

[philips]

https://bitcointalk.org/index.php?topic=216474.msg2272704#msg2272704