Option Coolbits 1

[jimerickson]

i assume that Option "Coolbits" "1" doesn't work with the latest driver and the gtx480 fermi card?

[nico342]

I tried about a month ago with my GTX 470 and that wasn't working.

[jmcharron]

Confirmed, Coolbits doesn't work with my GTX 465 running the 256.35 driver.

[kromjuice]

So can someone please tell me how do I control the clock speed of Fermi cards under Linux? I actually want to underclock a 480 for a CUDA project I working on, but it is vital I do this under linux.

Thanks.

[nico342]

I didn't try it with 256 series yet.

[Ulukai]

Coolbits 1 is not working indeed, but if you really are into changing the clock freqs, you should flash the bios.

Create DOS boot disk / USB disk with nvflash on it.
Extract the BIOS from your card.
Use nibitor 5.6 through Wine for changing the values.
Save the edited BIOS to your DOS disk.
Flash the new BIOS to your card.

I did it (except, I used GPU-Z in Windows for extracting the BIOS and ran nibitor in Windows because I don't like Wine) and I'm running my GTX 470 now @ 700/1700. Underclocking is possible too.