Bitcoin Forum

Other => CPU/GPU Bitcoin mining hardware => Topic started by: ron on June 13, 2011, 03:51:09 AM



Title: Underclocking 6950 to get better temperatures.
Post by: ron on June 13, 2011, 03:51:09 AM
I'm currently running 2 6950 MSI TF3s (http://www.newegg.com/Product/Product.aspx?Item=N82E16814127575&cm_re=msi_6950-_-14-127-575-_-Product) in a crossfire setup and am trying to find the best way to under clock them inorder to keep the heat, power, and noise down as much as much as I can. I haven't been able to unlock these cards and I can't figure out how to change the voltage or what to do with if I could change it. Mine on both cards when I'm not at my computer, only 1 when I go on youtube/movies, and turn it off during games.

I don't know if there is some ratio I need to follow as to under clocking the memory or the core. I just don't want to damage these cards that much.


TLDR: How can I underclock/undervolt my 2 6950s to keep the temps and fan lower?


Title: Re: Underclocking 6950 to get better temperatures.
Post by: dank on June 13, 2011, 04:43:49 AM
Google MSI Afterburner.  I used it for my two 6850's and am getting 420mh/s.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: PC Surgeon on June 13, 2011, 05:06:31 AM
Google MSI Afterburner.  I used it for my two 6850's and am getting 420mh/s.

Mistype? You mean 6950's right? Would be hard to believe you are pulling 420mh/s from 6850's.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: ron on June 13, 2011, 05:17:27 AM
what settings are you using? I'm trying to under clock as the sacrifice of Hashes for less Heat and Noise.

I'm currently running at:

Core Clock 750
Memory clock 800
Fans locked at 55%

Been running for 30 minutes getting about 80 Mhash/s less (currently 550) then with full clocks.

GPU 1 getting 64c
GPU 2 getting 75c

Sound level is as high as I care for it to be.


Are these settings ok?


Title: Re: Underclocking 6950 to get better temperatures.
Post by: dank on June 13, 2011, 05:41:35 AM
Google MSI Afterburner.  I used it for my two 6850's and am getting 420mh/s.

Mistype? You mean 6950's right? Would be hard to believe you are pulling 420mh/s from 6850's.
Nope, two 6850's. I'm now getting 437mh/s.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: TheGer on June 13, 2011, 06:53:55 AM
Thats an accurate Hash range for 2 6850's depending on model and OC.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: qed on June 13, 2011, 09:39:41 AM
what settings are you using? I'm trying to under clock as the sacrifice of Hashes for less Heat and Noise.

I'm currently running at:

Core Clock 750
Memory clock 800
Fans locked at 55%

Been running for 30 minutes getting about 80 Mhash/s less (currently 550) then with full clocks.

GPU 1 getting 64c
GPU 2 getting 75c

Sound level is as high as I care for it to be.


Are these settings ok?

I have few HD6950 and underclocked are working great, my settings:

Core Voltage: 0.925V
Core clock: 700MHz
Memory clock: 625MHz
Temperature: 62°C - 70°C
Fan from 32% to 40% depending on the room temperature.

Undervoltage is the key to reduce heat and noise.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: melco on June 13, 2011, 11:05:46 AM
All of my unlocked 6950 2Gb ref. are working at 370MHz Mem.. To achieve it you need to downclock it first to 625MHz in Afterburner, then close the program and reopen it. After that you can further downclock it to 370 and even 300MHz. It would definitely reduce your temps..


Title: Re: Underclocking 6950 to get better temperatures.
Post by: ron on June 13, 2011, 05:02:33 PM
Exactly what I'm going for qed. How were you able to change the voltage? I'm using MSI afterburner on windows 7 64.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: qed on June 13, 2011, 09:36:12 PM
Exactly what I'm going for qed. How were you able to change the voltage? I'm using MSI afterburner on windows 7 64.

To enable voltage control open Afterburner and go on "Settings". "General" tab, check "Unlock voltage control".


Title: Re: Underclocking 6950 to get better temperatures.
Post by: ron on June 14, 2011, 12:57:34 AM
Doesn't do anything  ???. Should have mentioned that sooner that I already tried it.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: Basiley on June 14, 2011, 01:56:38 PM
Doesn't do anything  ???. Should have mentioned that sooner that I already tried it.
maybe TF3 unsupported by AB, yet ?
try beta-version of MSI AB.


Title: Re: Underclocking 6950 to get better temperatures.
Post by: ron on June 16, 2011, 06:19:58 AM
I'll try the beta tomorrow it's to late for me.


For some reason when I'm trying to overclock my cards I'm getting BSOD every time. 10% underclock, 1% underclock....I dunno wtf is going on. Was fine yesterday and earlier today. Installed 11.6 yesterday.