I have a 2009 octocore Mac Pro. A few weeks ago it started making a constant noise. It sounds like a fan. The computer is not particularly hot. I checked with Temperature Monitor and CPUs/disks/etc. are around 40C. Only the Northbridge chip and sink are at 73C and 65C.
Is there anything obvious that my Mac needs or that might have caused the fan to get so loud?
Best Answer
In this Apple support article, Apple says that resetting the SMC can fix fans that are constantly spinning for no reason.
Here's what it says about how to reset the SMC on a Mac Pro: