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Tuning Mac OS Snow Leopard for SSD

Perform these changes at own risk! You may wreck your system, so make sure to have a current backup!

I just upgraded my mid 2010 15" Macbook Pro with an OCZ Vertex 2 SSD and 8 GB of RAM. Browsing the net for hints how to optimize the system when using an SSD, I applied the following changes to my system:

  1. Installed Trim Enabler from to activate trim support on Snow Leo with non-Apple SSDs.
  2. Deactivated sudden motion sensor (only if you have no harddisks left in your system). Use pmset -a sms 0. You can even store this in /etc/rc.local to ensure it is not changed.
  3. Mount the SSD filesystem with noatime option set. Write the following to a file /Libary/LaunchDaemons/com.nullvision.noatime.plist:

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
    <plist version="1.0">

    followed by a

    sudo chown root:wheel /Library/LaunchDaemons/com.nullvision.noatime.plist

There are also some things that I haven't tried out yet, but that might also speed up things or that might be beneficial to the lifetime of your SSD:

  1. Remove sleepimage:

    $ sudo pmset -a hibernatemode 0
    $ sudo rm /var/vm/sleepimage

    Be aware: this may result in data loss if running out of power during sleep as nothing is written persistently to disk.

  2. This blog entry describes in detail, how you can moving temporary dirs into a ramdisk:

Most of the tips were taken from

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