os-x-enable-trim.txt

Enable TRIM on non-Apple SSDs in OS X 10.8.2 Mountain Lion.

WARNING: This is ONLY tested on 10.8.2 (IOAHCIBlockStorage version 2.3.1), and NOT earlier or later versions. 

Check /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/version.plist 

Technical note: The driver changed in 10.8.2 and similar perl commands that worked in earlier OS X versions did not work for me once I updated to 10.8.2.

Run the following commands in Terminal…

1. Backup the original driver

    sudo cp /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage-backup

2. Modify the driver


sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61\x6C\x00{1,20})[^\x00]{9}(\x00{1,20}\x54)|$1\x00\x00\x00\x00\x00\x00\x00\x00\x00$2|sg' /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage

3. 2 commands to clear the system caches to enable OS X to pick up the modified driver

    sudo kextcache -system-prelinked-kernel
    sudo kextcache -system-caches
    sudo touch /System/Library/Extensions/

4. Restart the Mac