Sign in with
Sign up | Sign in
Your question

How to undervolt Powercolor 7870 myst

Tags:
  • GPUs
  • How To
  • PowerColor
  • Graphics
Last response: in Graphics & Displays
Share
April 20, 2013 6:58:52 PM

I'm trying my hand at low-key bitcoin mining and am wondering how to undervolt my Powercolor 7870 myst edition GPU.

The situation is a little hard to explain but I'll try my best. My wife uses my computer so I would really like to keep the "mining" as incognito as possible. Right now I have the GPU set at 850 core clock, 750 memory clock, 45% fan speed via MSI Afterburner @ 72C. I end up at about 350 Mhash/s and the fan noise is just above what I would call "normal" operation. My wife commented on the fact that the computer seems to be making more noise than normal...

I can't for the life of me figure out how to undervolt this tahiti GPU so I can lower the fan down to a more "less noisy" speed. In Afterburner it gives the option to "unlock voltage control", but as far as I can tell it does nothing. The top slider in Afterburner is "Core Voltage (mV)" but I still cant adjust it.

Is this something I have to do in Bios? Is there a way to be able to do it in Afterburner?

Thanks for any help

More about : undervolt powercolor 7870 myst

April 21, 2013 12:45:26 AM

The card is likely voltage "locked"
Try setting the gpu speed to 501MHz or lower and see if that allows voltage control (this method works on my locked 7870 and 7850).

If this don't work or make you happy then you're left trying to get/make a modified vga bios
There are some software methods that might override bios or force things (i'm not familar with the options for windows users).

And if none of that works, then you're pretty much out of luck unless you start soldering on your video card (seems most everyone only does this to raise voltages).



m
0
l
April 21, 2013 10:03:51 PM

^undervolting is quite possible with software.
Try somethign else first though. In CCC, set the power tuning feature to -20%. This should limit you temps and is quite a bit easier.

you can also look at this: http://efmer.eu/boinc/
I believe it lets you throttle your GPU at whatever % you want.
m
0
l
April 24, 2013 9:53:34 PM

If none of these options work, you could always reflash the bios to an unlocked version. But anyway, how do you clock lower than 600 megahertz because that is the minimum clock level that can be set by the user on afterburner on my 7870.

Wait, reinstall the drivers and everything for the card because I had an issue where my 7870 would not identify as a hawk and unlock the voltage. Try using afterburner after your reinstall everything and see if identifies what type of card it is like a 7870 myst or just a 7800 series.
m
0
l
!