It's similar to the tinking sound that comes from electric baseboard
heaters when they heat up, except the CPU can heat up a lot quicker.

Maybe, but the radiator thing only lasts for a few mins, while it's
changing temps, then it stops. This seems to continue.

Yeah, if the tinking sound continues more than a couple of minutes or so,
it's probably not thermal expansion. Still possible, I guess, but doesn't
seem likely that expansion would continue over a long time frame.

No reason to fix it, you woudln't even notice it unless you went
looking for it. And it only happens with heavy SSD activity, which is
rare here. It might happen with other heavy data movement, or CPU
activity, but the SSD activity is the only place I noticed it.

I don't know if it would be related to your situation, but my CPU fan is
completely silent under normal loads. If I put the system under a heavy
load the fan speeds up, and starts making a vibrating noise. It either has
bad bearings or is out of balance. I keep meaning to swap out the fan, but
since it only happens under heavy loads I haven't been motivated enough to
change it out.

I suppose if your fan was severely out of balance under heavy loads, it
might be contacting the heat sink and making a tink, tink sound?

Anthony Watson
www.watsondiy.com
www.mountainsoftware.com