On Thu, 13 May 2021 16:31:56 +0100, Harry Bloomfield, Esq., wrote:

New laptop, busy setting it up and I'm finding the fan noise very
annoying and constant on mains. On battery it is intermitant.

In the BIOS I found a setting 'Fan always on' with the option of on/off.
Setting it from its default on to off, it does seem a bit
slower/quieter. Am I OK to do this?

Yes, it won't cause a problem.

If the CPU heats up then the fan will come on to cool it. It's possible -
likely, if you're a heavy CPU user - that the fan won't be on all the time
but runs much faster when it does come on.

There'll be a cutoff point where the PC will power off if the CPU gets too
hot.

I use a monitoring tool HWINFO to see CPU core temps, fan speeds etc. It's
at www.hwinfo.com but if you're wary (as I am) of clicking random URLs
then Google for Dell HWINFO, the link 'Steps for analyzing overheating or
loud fan...' points to a Dell site which references (and links to) HWINFO.
So a more believable source than a random Usenet reply :-)