I use a precision tower 3620 at my office, and it seems the built-in CPU fan curve is totally flat: Whether the CPU temperature is 30°C or 75°C, the CPU fan stays at a constant 1350 RPM, give or take 10 RPM. All I want to do is make it so when the CPU gets hotter, the fan spins faster, which seems so fundamental that I feel silly asking for it--Sort of like asking if there's a way to make it so the speakers get quieter when the volume is set to a lower value.

There's an option in the BIOS for "Fan Control Override", which sounds like what I'm looking for, but actually serves only to raise the fan speed to the maximum (3800 RPM), but once again, the "curve" stays totally flat. Since the fan is rather deafening at that speed, subjecting myself and my coworkers to that for 40 hours a week isn't a real option.

I tried downloading HWiNFO64 and setting a custom fan curve, but found that for any given temperature, I'm only able to set it to one of 3 speeds (0 RPM, 750 RPM, and 3800 RPM). Based on what I've gleaned from existing threads on this topic, it's my understanding that this extremely narrow quantization is explicitly defined by what the Dell firmware allows other applications to set. Is there any way to override this? Does Dell provide any tools that allow options other than "always 1350 RPM" and "always maximum RPM"?

Please let me know if there's any other info about my system that I can provide to help resolve this issue. And I do apologize if I sound impatient--I've been working on this issue for months with no success, and I'm really hoping that I won't have to get specialized fan control hardware just to achieve one of the most basic functions a CPU fan is supposed to provide. Any help is appreciated.