I have recently repaired a damaged nVidia Quadro 4000 video card. (Fermi based card, released 12 years ago). I plan to use this card in my main pc for various reasons.
The card works fine, there is however a problem with temperatures. nVidia by default lets this card to reach 85c before it starts to ramp up the fans, and 95c before the fans fully throttle. This is obviously too hot. Under full load, the card becames so hot it hurts to touch the card.

-Obviously i have added new thermal paste on it, it only decreased the temperatures by like 1-2 degrees.

-I have tried to downvolt the card in videobios, as lowering the voltage will lower the temperatures as well. I have used nibitor to mod the bios. I modified every voltage down by 0.1v. Unfortunately, the card ignores the voltage settings. After flashing the bios with newest nvflash, it doesnt matters what settings i set, the voltage always stays factory stock default, and the card continues to run hot (i can set the clocks, that works, but that doesnt helps here).

-I have tried to hard-modify the pstate slots in the video bios as well. It doesnt seems to have any effect. (i will test it again later)

-I have tried to mod the fan settings in videobios, no luck either. All the settings are grey. I used third party software to change fan curves (max throttle above 85c), that worked, the card is now however very loud. Voltage settings would be better.

-Even with third party software, voltages canot be modified in the system on the fly.

-Fermi video bios editor doesnt works with the bios of this card.

-Tried random Quadro 4000 bioses. None of them helps.

Has anyone succesfully downvolted this particular card, or any other fermi based cards with vbios mod?