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Easy undervolting guide for 79xx and R9 280X cards

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Flash back to the original bios, or move the bios switch to the other position to see if it does the same thing. Always reboot between flashes :p

When I flipped the switch, the card continued to act in the same way; with the .95V cap and such. And yes I did reboot, but thanks for the double check.
 
hey Tim, didnt the reinstall of drivers help ? or you didnt try flashing again ? you should, that was just the drivers stuck in 2nd gear
 
hey Tim, didnt the reinstall of drivers help ? or you didnt try flashing again ? you should, that was just the drivers stuck in 2nd gear

I'm going to build another rig today, but while I wait for windows to install, I plan to pull 2 of the cards and try the flash again. After flashing, I'll reinstall the drivers and see what happens.
 
I'm going to build another rig today, but while I wait for windows to install, I plan to pull 2 of the cards and try the flash again. After flashing, I'll reinstall the drivers and see what happens.

it should work, i believe that time it worked too, only if you reinstalled the driver after the first flash
drivers can be a pain
 
Easy procedure, specially if using Winblows and atiwinflash.
No need to make a DOS boot disk (which can be a pain atm), and works just as good :D

  1. Download and run GPU-Z
  2. Extract the gpu bios using the button with a bios chip.
  3. Create an atiwinflash folder and extract its files there.
  4. Download and run VBE7 and open the extracted bios file.
  5. Go to the powerplay tab, and change the voltage you see in the last power state (one with highest clocks) to match the previous one.
  6. Save the bios with an easy to remember name and copy it to the atiwinflash folder.
  7. Open CMD as an admin.
  8. Go to atiwinflash's folder (you guys know DOS right? cd.. cd.. cd atiwinflash)
  9. Run the following command: atiwinflash -p 0 moddedbios.rom
  10. After that change the -p number to 1,2,3 or whatever, to flash your cards one by one. (it's safer to do it that way, but you can also try -pa which flashes all amd cards at once)
  11. Try mining at your usual settings, if it doesn't hang you can let it be or try lower. I just leave my R9 280X XFX cards at 1143mv and they mine happily at 738kh/s using 210w from the psu vs 250w.

Links:

VBE7
GPU-Z
Atiwinflash

There's graphical interface for atiwinflash, is there a reason why not to do it graphically?
Also, how to tell which card is in which slot / port number?
 
I don't like GUIs...I've gotten used to the old school command line for atiflash/atiwinflash.

Knowing which card corresponds to which device number, that I never bothered with. Unless you run mixed gpus. I'd reccomend flashing separately if that's the case.
 
Save time money and effort and use BAMT instead of windows!

I have more free copies of windows than I know what to do with, so money isn't an issue. As far as time goes, I just install while I play a video game (but I do realize that I lose 2 hours on installation). As far as effort goes, I don't know squat about Linux, but I don't see why I cannot give it a shot with a spare USB stick.
 
did the bios change on my 7950, dropped from 1.25 to 1.15 (I believe) and temps dropped significantly. Thanks Ivan :)
 
;)

The amount of over-volting AMD cards ship with is ridiculous imho...I've tried tons of 79xx and 280X cards and all of them run stock clocks and even a mild oc with lower than stock voltages.

It's like they say, "oh, screw testing, just push 1.2v through the darn thing and forget about it", and then go home early and have some pizza.
 
xD

I wanted to get some pizza but we ended up eating some soy burgers with french fries instead...

Need some coca cola now, brb.

I'll try to include bios flashing tips for R9 290/X users but first I need to figure it out myself. Can't get the one on my client's rig to do more than 800kh/s constantly without it downclocking. It's at 765kh/s till I can go to the farm on Monday and unplug the monitor from the igpu, otherwise I can't change clocks nor fan speeds.
 
Hi Guys,

Great thread, I currently have 2 x XFX and 2 x MSI 280's running in my rig, the hash rates are good and the temps aren't to bad I believe, the only thing bothering me is one of the cards seems to run quite abit hotter at the moment they roughly run like -

GPU 0 - 67c
GPU 1 - 84c
GPU 2 - 63c
GPU 3 - 60c

One thing I noticed the pool I'm in has just been taken down yet looking at the cards now the hottest card has now become the coolest by 2/3c even though the fan is spinning at 800rpm less than the others which seems strange?

Anyone got any ideas as to why the card runs so much hotter than the others? I've tried using trixx to underclock the cards but that didn't seem to work either.
 
Think it's worth trying to mess about with the bios card at that temp or would you leave it? I'm pretty average with computers so doing the guide in the first post might be quite slow and painful lol
 
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