I have the Gigabyte 965 S3 motherboard. I have the same problem as you. I have a front case 80mm fan and a 120 mm rear case fan. Upon installing the F5 bios, I rebooted the computer and found a definite increase in noise. I checked in easy tune and it is the system fan that is spinning at max speed. Using the F4 bios, the computer was virtually quiet. With the F5 bios I found it to be too loud and then I flashed it back to the F4 bios. I read that the F5 bios was to make overclocking the e6300 and e6400 more stable. Maybe this was done to have more air circulation inside the case. I haven't experienced any stability problems with either F2 or F4 bios when overclocking my e6400 to 400Mhz FSB.
f5 works perfect for me no probs
Are you having the BIOS control the fans? Also, are you sure you're running the F5 BIOS and not your backup BIOS?
yer my fan is and it seems fine, no rise in volume for me as far as i can tell
I have the same board with f2 bios. My problem is the machine runs very quiet and idles at 27 degrees and 40 under load but I want to verclock it. I have a Nvidia 7900GS but the board can't overlock with this card and bios f2 and if I upgrade to any other version the fan come son full blast the whole time and is very noisy. Anybody find a way around this? I really don't want to change either the board, gfx card or cpu cooler just to overclock.