my gigabyte gtx 560 ti runs at 40% speed when idle, it sits about 30C which i'm none too bothered about but the noise that comes with this minimum speed is driving me nuts!

searched for a utility to flash the bios to lower the speed called nvidia bios editor (v6.02) and its really confusing, i can read the info from the card into the program itself, however not all field seem to populate with data (the min/max speeds do..)

then i've read about how the 5xx series cards are unsupported and needs a donation to gain access to a 5xx compatible version of the program.

so i'm wary about using this program on two counts because a) it doesn't seem to load all the info from my card and b) is the version publicly available compatible?

With an nVidia 5xx series card, not the Gigabyte 560Ti, I find that with nVidia Bios Editor (NibiTor) 6.02 the Clockrates and Voltages tabs are greyed out. Advanced Info apparently reports the correct details. Timings are greyed out. On the Temperatures tab the minimum and maximum fan speeds are editable and nothing else. They are shown as PWM duty cycle %. So it looks to me that if you are seeing the figure '40' in the min fanspeed box you should be able to change that to say '30'. There is a Boot Settings tab with everything apparently editable but I would be inclined to leave that alone. Otherwise I suspect I am seeing what you are seeing.

NiBiTor includes the facility to save the existing BIOS (File-->Save BIOS) and it would obviously be wise to do this before attempting any changes. In addition, Gigabyte have a downloadable @BIOS utility for their GTX 560 Ti cards. This Gigabyte utility, as I understand it, will also enable you to save the existing BIOS, and load a BIOS file again if required.

i'll have a check when i'm at home to report back whats greyed out and what isnt. the fan speed box is editable, just a bit wary if stuff other is greyed out, ie, will it blank those settings out..

I don't think NiBiTor will change anything in the BIOS apart from the fanspeed settings. The greying out of other settings is I suspect just an indication that they are uneditable, so saving the BIOS after a fanspeed change should not affect them.

If you are not using it already it already could I suggest you download the free CPUID graphics card utility GPU-Z. The Sensors tab on GPU-Z will show not only the fan speed PWM duty cycle % and rpm but also the changes in GPU core speeds etc as the card cycles between the different power states P0, P1 and P2. If it does this exactly the same before and after any BIOS modifications this should confirm that your GTX 560 Ti is operating exactly as it should apart from the different minimum fan speed.

its a shame its not useable under win7 x64 yet, i had to install xp just to get as far as i did, then i chickened out

Hi, when I was sorting out the BIOS on my GTX260 under Windows x64 I used a bootable flash drive.
Boot off flash drive to DOS and dump bios to file using nvflash
Boot windows and edit BIOS and save to new name.
Reboot off flash drive to DOS and flash new BIOS back to card.

Card runs ~20 higher clocks, 25% min fan speed and lower trigger temp to increase fan speeds and enables slow fan speed changes. Does have the advantage of running 2x92mm fans on aftermarket heatsink....

All worked out fine!
Seb