You're probably hearing the cooling fans, not the processor, cooling things off after rendering. Make sure everything is clean. I clean my machines every 60 days.
Appreciate the reply, but it's definitely not the fans. The fans have a whirring noise. This is a crunching processor, working-its-tail-off noise, and again, it's slowing down everything else I try and do with the computer. Opening Photoshop will take a solid 90 seconds, and that can't be because of the fans, can it?
What Rick is saying is that your processor could be getting overheated and it's having to work extra-hard to do simple things because of it.
Processors don't make a "crunching" noise. They don't make any noise.
Hard drives, however, do make a noise. (That's assuming they're the kind with disks that spin and a seek head; solid state drives are, naturally, silent.) Operating systems can use hard drives as a sort of RAM substitute when they need to. So, perhaps your RAM is overheated and your system is having to resort to using the hard disk. Or something is odd in your caches, etc.
What exact version number of AE are you running? 12.2.0? 11.0.4? 10.5.1?
Okay, I gotcha. Thank you for that clarification. I should have known processors don't make noise, that was silly of me. I was just trying to explain the sound that's being made.
Your description makes sense.
I'm running AE CS6, more specifically 18.104.22.168.
I was hoping you were running a less up-to-date version because that might indicate caching issues or something. Oh well! Back to Rick's suggestion that your computer may be overheating or otherwise dealing with stress. Carefully open her up and clean her out (with canned air - not by blowing or hoovering of course ).
Bump. I'm having the same issue. I have a 2.7Ghz i7 with 6GB RAM, CS6. Not a beast of a system, but decent. OS X 10.8. After rendering out the queue, my computer will just grind to a halt. Only a restart will get me back up and running. Even if I purge all memory. It's quite frustrating.