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.

  • Something I would like to know too
    – revolver
    Mar 21 '12 at 8:39
  • On a side note, is there a reason you have to run Sophos?
    – jmlumpkin
    Mar 21 '12 at 12:25
  • @jmlumpkin: I like my system to be free of malware even if it may not necessarily target a Mac, since I use PC's as well. Besides, I think it's only a matter of time before Macs will be targeted just as much as PC's are, because they are becoming more popular. Many other people recommend running Anti-Virus on a mac as well.
    – Senseful
    Mar 21 '12 at 22:17
  • @Senseful understood. In 16 years of using Macs though, I have never used antivirus. I also interact with Windows machines daily. I do agree that this may be more of a threat in the future. Luckily Apple has already started taking more precautions with signed applications and the MAc App Store
    – jmlumpkin
    Mar 21 '12 at 23:28

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&tstart=0

  • 1
    Came here to state the second paragraph. Make sure you tell Sophos to ignore your spotlight metadata.
    – jmlumpkin
    Mar 21 '12 at 12:25

How to Run the Spotlight indexer at a lower priority to reduce CPU load on your Mac


This procedure has been successfully applied to OS 10.8 (Mountain Lion), OS 10.7 (Lion), and OS 10.6 (Snow Leopard).
Do NOT attempt this procedure on OS 10.9 (Mavericks)! The mds daemon functions differently and cannot have its processing priority lowered. Attempting this procedure will only cause your computer to malfunction.


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