wondering if anyone here jas had this happen to them?
cpu fan is nice and quiet prior to render (2500rpm) hit render, fan speeds up to approx 4000, gets noisy, render finishes and even an hour or two later the fan is still at 4000rpm, freakin thing never returns to its normal speed
am using an Intel Heatsink and fan,
ta,
Tom
Maybe something funny in the bios.. check that.
Also might be a good idea to update the bios and see if that helps. As that is what generally controls how the fans work.
Have you checked out the CPU temp? Perhaps it’s still hot in there.
Last week I actually turned off the temp sense in the BIOS so it’s always on full speed. I don’t hear the darn things at all. I figure I’d rather replace a $10 fan than a CPU and mobo.
Except if you cant hear the fans then you wont know if they stop/die.. then you will have to replace fan and cpu 
That being said, its often good to run speedfan in the system tray to keep an eye on cpu temps and fan speed. That way you know for sure 
And its easy to setup to display the current cpu temp in the system tray, and however over it can display cpu temps, core temp.. fan speed..etc..etc..
has anyone ever tried to make a home made blade server case with AC unit?