fan speeds & temperatures - need advice

i got a new computer and it has a knob on the front to control the fans.
i like to turn the fans down nights that i leave the comp on all night,
cause it's right near my bed, and i like it to be quiter. i'm just
wondering how far i can turn them down and it not be bad for the
system. it says in the manual if the temp of the cpu reaches a certain
level it'll throttle down the performance to allow it to cool. so it
sounds like you could turn the fans down quite a bit and it would stay
cool, but i dunno about other components, like the ram or hard drives.

there's an lcd display on the front showing the temperature. i don;t
know if it's working correctly tho. for one thing, it stays between 74
to 80, typically only as high as 78 though. one night that i even had
the fans turned down i saw it on 68 tho. earlier today i checked it,
the lcd said 76 (F). yet in the bios it said:
CPU: 109
System 1: 86
System 2: 78

i had thought the lcd display was for the cpu, but obviously not. i'm
just looking for any advice on fan speeds and temperatures. thanks.


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gnznroses