My BIOS doesn't have that option.
The HSF is a stock one from Intel Pentium G620.
You might have to do a bit of "old school" testing.
Open speedfan, run something CPU intensive, bull the CPU fan cable out, stick your fingers on the CPU heatsink and compare the heatsink heat with what speedfan says, once its nice and toasty (uncomfortable to touch for more than half a second) then plug the CPU fan back in and make a note of the fan speed.
That will tell you the maximum fan speed, google (or check SPCR) to find out what the maximum fan speed is supposed to be for that fan, if that matches what speedfan is reporting then you know that the fan speed that speedfan is reporting is correct.
Once you have done that you will know enough to make some decisions.
You should know whether speedfan is reporting the fan speed correctly, you should be able to identify whether that high temperature that speedfan is reporting is correct or not via "finger burning" as well as whether that temp rises inline with the other CPU temps or not (in speedfan), if it does not then it is bogus and you should ignore it.
That only really leaves 2 directly related points, does the CPU heatsink/fan cool enough for your needs and is it quiet enough.
Both of those points can be addressed by either replacing the heatsink/fan with something that is better/quieter, or make the exiting CPU fan quieter by another method.
I hope this helps.