Ubuntu 12.04, AMD Phenom II X4 955 Processor × 4.
I've begun noticing over the past few days that when I leave my PC for a while, the CPU fan is running full blast when I come back. I installed Psensor to check what was going on.
When I'm using the PC for light work such as browsing, the CPU runs at around 37-40C. But when I leave it for a while and come back (around an hour or so), I'm getting pretty consistent temperatures of around 46C. I have no programs running on it, and the screen is dark. Once I start using it again, the temp goes back down to between 37-40C
Now, I know 46C isn't that high, but I just find it strange that it runs cooler when I'm using it, even for light work, than when it's sitting idle.