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Hi everyone!

- Bounty for a solution: 0.03 BTC

Does someone know, how to lower the core voltage for a MSI R9 280x under Linux? I have 10 cards. 5 of them are s/n 602- V277 -28SB (great!) and 5 cards are s/n 602- V277 -38SB (bad!). Any other ideas how I can make this? Windows is not an option anymore.

Some facts:
- Factory voltage for MSI R9 280x (revision 28SB) = 1.2 V
- Factory voltage for MSI R9 280x (revision 38SB) = 1.25 V

I tried with latest VBE7 and set the voltage in the "State 1 - Performance" tab to 1062 for #6 and #0. After flashing the modded bios Vgpu is still at 1200 mV when measured directly on the card with a multi-meter. Power consumption at the wall is 270 Watts. However, GPUz shows 1062 mV. Afterwards I set the voltage to -100 in Afterburner. The card now reads 1097 mV (measured with the multi-meter again) and the power consumption dropped to 235 Watt.

My last try was to set #0 to default (1.2 V) and only mod #6 to 1062, but no chance. My multi-meter shows 1.2 V on the 28SB- and 1.25 V on the 38SB-cards.

I have no idea why the card ignores the VBE settings. Any advice would be appreciated.

http://www.techpowerup.com/forums/threads/vbe7-vbios-editor-for-radeon-hd-7000-series-cards.189089/
http://rumorscity.com/2013/12/09/how-to-modify-video-bios-to-undervolt-gpu-in-linux/

I already googled those results. VBE7 had no effect on the new cards (38SB) or I did s.th. wrong. Are there any other options? Or can someone verify 100% that VBE7 works with both revisions of these 280x's?

vbe7 doesnt change your bios by itself, it just loads the bios files. you have to boot up with ATIflash and use
atiflash -f -p 0 newgpu0biosname.rom
to flash your first GPU with the new bios named "newgpu0biosname" that you just edited with vbe7. You can dump your bios with gpu-z and open it with vbe7, edit, and flash with the bootup usb disk like this

Yep, I've used VBE7 to undervolt a number of 280x, all of which with sucessfull results.

Download Rufus, and burn a FreeDos USB stick. Copy the newest AtiFlash 4.17 on there.
Boot off it, and save the GPU's BIOS.
Open that BIOS in VBE7, and tweak the clocks/voltages.
Use FreeDos again, and use AtiFlash to flash your adjusted BIOS. Bam. No issues.

Hi, I tried again with VBE and set the voltage in the "State 1 - Performance" tab to 1062 for #6 and #0. After flashing the modded bios Vgpu is still at 1200 mV when measured directly on the card with a multi meter. Power consumption at the wall is 270 Watts. However, GPUz shows 1062 mV. Afterwards I set the voltage to -100 in Afterburner. The card now reads 1097 mV and the power consumption dropped to 235 Watt. I have no idea why the card ignores the VBE settings. Any advice would be appreciated.

BTW: All cards are from MSI.

You followed all the steps? Used VBE7 to edit the BIOS, then you saved it as a new BIOS file? Then you use some sort of VGA BIOS utility to flash the modified BIOS back to the GPU?

Did you turn the switch to the second bios and update that one?

you have to flip the switch to change the settings see the image.

https://i.imgur.com/4ow2BPu.jpg

Yes, I modded the BIOS which I downloaded here (http://rumorscity.com/2013/12/12/msi-r9-280x-bios-update-to-fix-overheating-and-vrm-temperatures/) with VBE. I flipped the switch to "2" and flashed it. To proof to myself, that flashing works, I changed the core clock successfully from 1050 to 1000. That works fine. But to change the core volts doesn't work for me.

Later today I will backup the original BIOS from switch "1" and try to mod this and and flash it on switch "2". But I think this will not solve the issue.

Well, I tried to mod the original BIOS from switch "1" and flashed it on switch "2". After the Windows-Start-Screen I have only a black screen. Windows doesn't start. Afterwards I deinstalled the AMD driver, deinstalled Afterburner but no chance. Now I am back at the beginning of this thread.

No one around, who undervolted R9 280x's with VBE successfully without using Afterburner (measured lower volts directly at the cards)?

BTW: The factory settings of the 28SB-cards are at 1.2 V - the new cards (38SB) are at 1.25 V...

GB 280x. Dropped from 1.14V to 1.01V using VBE7 on 6 GPUs using their modified F.60 BIOS. CGMiner reads the new voltage as lower. GPUz sensors read the new voltage as lower. The lower temps prove it's working, and my kill-a-watt says that the 40W drop in power consumption per GPU, so we know it's working.

Not sure why it's not working for you. Your GPUs might use a non-standard voltage regulator? Or a non-standard BIOS that VBE7 can't modify properly? Neither of those guesses sound correct, but you never know?

Same here, VBE7 worked flawless on all my Sapphire 280x & 7970s.

I Hope it works on MSI.  I plan to buy their cards for my next rigs.

Update:

- Bounty for a solution: 0.03 BTC / 1 LTC
- Added more infos in first post

I also have v277-38sb ( msi r9 280x )and need solution to undervolt since it get too hot. So far no way to lower it, other version of msi r9 280x adjust voltage is ok, maybe there is different volt. regulator on board?

Hello everyone. I made a post regarding this card.

I've had a positive experience flashing the bios. Please ensure you use the correct one (I linked it in my post below).

https://bitcointalk.org/index.php?topic=468636.0

I have been able to undervolt many cards (dual-x, his ice-q, gb windforce, powercolor), the only one I couldn't was the msi r9 280x. It had a bios that was twice the size of a normal bios when saved with atiflash / vbe7. (256 kb instead of normal 128 KB). When I tried to flash, it got nothing but crashes, and sometimes wouldn't boot.

Try this one: http://www.techpowerup.com/forums/threads/radeon-hd77xx-78xx-79xx-bios-editor.183423/

You'll still need a Windows machine to read the ASIC on each card (with GPU-Z) and undervolt according to those values.

VBE7 works but is still a bit limited.

I made a mod for the MSI R9 280X Gaming OC 3GB equipped with BIOS v015.040.000.000.003435 (Part Number 113-C3865000-X77 --- S/N: 602-V277-38SB-140101xxxx). It's supposed to get your voltage down to 956mV.

If you want to give it a try, you can get it here: https://dl.dropboxusercontent.com/u/2780744/113-MSITV277MS.314_TAHITI_B0_XTL_C38650_GDDR5_3GB_956mV_EXPERIMENTAL.7z

Please take every precaution when flashing it. Make a backup, have instructions at hand how to unbrick your graphics card, should it go wrong. Unfortunately, I am unable to test this one myself as none of my cards are 38SB revisions.
In case it works out, can you give some feedback such as hashrate and difference in power consumption if possible?

I used the VBE method successfully on 28SB cards in the past, but it didn't work anymore on 31SB. I've been discussing it on Litecointalk and in the end managed to modify it in such a way that it works as expected.

So if you have an 31SB with BIOS v015.042.000.000.003435 (Part Number: 113-C3865000-O77 --- S/N: 602-V277-31SB-1402065411), try out this one (https://litecointalk.org/index.php?topic=12680.msg147978#msg147978). I'm running that BIOS myself since 48 hours now and got no problems.

Another user over there made a perfectly working 38SB v015.042.000.000.003435 (https://litecointalk.org/index.php?topic=12680.msg147679#msg147679) (Part Number: 113-C3865000-X77) for 956mV as well.

3x MSI R9 280x SB38

Without Afterburner, without modded BIOS: 960 W at wall
With Afterburner, without modded BIOS: 820 W at wall (35 W less at each card)
Without Afterburner, with modded BIOS: 880 W at wall (20 W less at each card)
With Afterburner, with modded BIOS: Not possible to go under 880 W at wall because AB is already at its limit with the modded BIOS.

So... your BIOS may work but the watts have to be lower as 880 W when it is at 0.956 V. It should be about 40 watt lower for each card. Not only 20 W.


I will test the modded BIOS from kqpahv the next days.

Thanks for the feedback punkrock. I've got some feedback as well on litecointalk and will go back to the hexeditor, as no or little difference was measured, just like you're confirming. Hopefully somewhere this week when I find some spare time. I'll get back asap as I get something that effectively works :)

Hi, I have to clarify this thing to all.

I have 8x msi r9 280 x SB38, and I am planning to buy all that I can get my hands on.

YOU CAN UNDERVOLT IT VERY EASILY.

Use the techpowerup rom, http://www.techpowerup.com/vgabios/149729/msi-r9280x-3072-131011.html

undervolt to 0.943 V with VEB method. Only this volt works.

-Flash to legacy slot (the one closer to the hdmi ports-etc) using atiflash

- intensity 13, tc 8192, gpu speed 925 memspeed 1500, 100% reliable 24/7 for weeks.

You will get 650 khash and unbeliavably low 150w consumption. ( I have 3x rig which uses 560 WATTS altogether)

- You can easily put 4x in a 750w PSU (or 3 with 650 w PSU) , provided that you can have enough pci-e 6+2 connectors (a bit tricky with cheap PSU's, most gold 850w psus have enough connections)

- mine away....