Is undervolting possible in Windows? or only Linux?

[adaseb]

I need to undervolt my 6990 because it uses way too much heat and loud.

In the past I was successful but only in Linux.

In windows whenever it booted, it would go to a blue screen. Actually any modifications to the stock vbios caused windows not to boot.

Is there anyway around this or can you only undervolt in Linux?

[Amph]

you need to flash the bios, and of course it's possible

atiflash or nibitor are your friends, do this at your own risk

[giveen]

Sometimes its not possible if its a locked card.

[Amph]

Sometimes its not possible if its a locked card.

you can if a new atiflash version is released, they always working on it, normally only new card are locked anymore, old cards should be all full unlocked

[toptekk]

Warning you do it at your risk these two links should be all you need to do it in windows for amd cards .



http://www.overclock.net/t/1353325/tutorial-atiwinflash-how-to-flash-the-bios-of-your-ati-cards

http://www.techpowerup.com/forums/threads/vbe7-vbios-editor-for-radeon-hd-7000-series-cards.189089/  this works on R9  as well I used it on my 280 with no issue .


Just depends which R9 . . did not work for my 290.

[adaseb]

I finally got it to work.

The GPU I have is weird. It has 2 BIOSES that you switch. Its the 6990 which is 2 cores. Its very loud and power hungry.

I think in the past I flashed the wrong bios when undervolting. This time I flashed the 2nd BIOS (the OC one) and windows finally seems to boot.

Huge difference. The fan is SILENT!

Temperatures are much better at 70C instead of running at 90C and peaking at 100C.

[toptekk]

I finally got it to work.

The GPU I have is weird. It has 2 BIOSES that you switch. Its the 6990 which is 2 cores. Its very loud and power hungry.

I think in the past I flashed the wrong bios when undervolting. This time I flashed the 2nd BIOS (the OC one) and windows finally seems to boot.

Huge difference. The fan is SILENT!

Temperatures are much better at 70C instead of running at 90C and peaking at 100C.

Most of them do now a days sense you figured it out i would use bios 2 i think that's one that lets you OC or does on my 280 my 290 is unlocked out of the box . .I only OC mine for gaming sense to me it seems to cost about the same to buy a few sha256 miner till some one comes out with a cheap more efficient miner then the A2 or titan then I'll buy some of them that might not happen till the end of year if then .