Undervolted linux rig help

[bercy]

Hi,

I've successfully overclocked my 6 Sapphire Nitro+ OC 4Gb (3 Samsung, 3 Elpida) so that I now get 27 to 29 MHs on all of them mining ETH with Claymore.  This was done by altering the memory straps and jumping the core clock to 1206 and the memory clock to 2050.

The cards were flashed with ATIWinFlash on Windows, and then transferred to my Xubuntu rig.

So far so good.

The problem is that before overclocking, I was pulling 900 Watts from the wall, and now I'm up to close to 1200 Watts.

I did play with undervolting while on Windows with Sapphire Trixx, and it was also a success, the watts pulled from a single card would go down significantly.

What I have trouble wrapping my head around is how to make the undervolt change permanent on the card, so that when I move the card to Linux, it remains undervolted.  I've followed many guides so far (notably 1stminingrig.com, or Badger's 4-part series), and succeeded with none of them.

My questions are :

1- can undervolting be achieved by modifying values in Polaris Bios Editor, and then flashing the rom with ATIWinFlash,
2- if so, what values should I change in PBE if, for example, I've determined that lowering the volts by 100 mV in Sapphire Trixx gives a stable result ?
3- if not, how does one go about undervolting cards on linux ?


Thanks for your help

[1713869646]

1713869646

[1713869646]

1713869646

[1713869646]

1713869646

[1713869646]

1713869646

[daupheus]

up need to share this experience.  

I've go simplemining with 4 rx580 and have 853W on wall.with OC (1140/2150) and dual mining ETH+DCR

the only solution is to mod volt directly on vbios ?

this is my ROM
https://www.daupheus.com/wp-content/uploads/2017/05/rx580firstmoddedspecial.rom.xz