Make Spotlight indexing use less CPU? Whenever spotlight begins indexing my files, my computer's fan starts spinning like crazy. Is there any way to essentially tell spotlight that it doesn't need to finish as quickly as possible, and that I would rather it take longer and use less of my CPU percentage at a given time? (I.e. reduce fan noise.)

One thing I noticed is that Spotlight was causing Sophos Anti-Virus's InterCheck process to run at near 100% CPU. By disabling Sophos' "on-access scanner", my CPU usage is less, but still hovers around 50% occasionally.
You cannot configure how fast Spotlight will index files. Normally, it should auto-throttle itself and not cause massive CPU usage (unless fully rebuilding indexes or doing first-time indexing).

If you run into trouble with Sophos and Spotlight, you could tell Sophos to ignore Spotlight's metadata folder. Also, note that there a lot of grief about Sophos interfering with spotlight: https://discussions.apple.com/thread/3562174?start=0&amp;tstart=0