Apple - MBP SSD upgrade - which settings to change?

Here you are some major points:

  • Reinstall your Mountain Lion.

  • Don’t run benchmarks on your new SSD

    Benchmarks usually write a lot of data to the disk (to test the write speed), wearing it out. So it is the best way how you can ruin your SSD even before you start using it. Don’t do it.

  • Enable TRIM

    OS X supports TRIM only for Apple-supplied SSD’s. If you want to have TRIM enabled with 3-rd party SSD drives - download Trim enabler from this site. Very experienced users may want to enable trim manually not using above mentioned enabler, here is the tutorial how it can be done by the hand.

  • Turn off local Time Machine snapshots [laptops only]

    There is no GUI switch to turn these local backups off, but it can easily be done on the command line. Just start Terminal.app and execute the following command: sudo tmutil disablelocal if you want to back to original settings use sudo tmutil enablelocal command

  • Turn off hibernation [laptops only]

    OS X saves all the memory to disk when entering sleep mode.The more RAM you have, the more gigabytes it writes to the disk every time you close the lid/put it to sleep. You can disable this feature via sudo pmset -a hibernatemode 0 command

  • Set noatime flag

    OS X by default records last access time for every file. Every time you read a file, a write is made on the filesystem to record this action. There is no point in doing it and no side effects if you disable that by mounting the root filesystem with noatime flag set. You can read more about it here and here:

  • Move user home directories to HDD [SSD+HDD only]

    This is only useful if you have both SSD as well as HDD in your Mac. You can move all the content of /Users folder to the HDD and create symbolic link from the SSD to it by running this 3 commands: sudo ditto /Users /Volumes/your_hdd_name/Users sudo mv /Users /Users.bak sudo ln -s /Volumes/your_hdd_name/Users /Users

  • Turn off sudden motion sensor [no HDD only]

    If SSD is the only drive in your Mac, there is no point in using the Sudden Motion Sensor. You can turn it off by sudo pmset -a sms 0

  • Turn off hard drive sleep [no HDD only]

    Some websites mention SSD may freeze when the hard drive sleep feature is on, so it is recommended to turn it off. It can be done in the System Preferences->Power settings->Put hard disk to sleep.

The full article about above mentioned tweaks can be found here


I installed a 256GB SSD into my first generation 17" unibody MacBook Pro a couple of years ago, before there was a third-party trim option. Since then, I've only gotten three speeding tickets for my computer being as fast or faster than the current machines.

The third-party SSD Trim Enabler has been the only change I've made to accommodate the SSD.

You may still want to keep the suspend to disk for hibernation ability. However, if your SSD is >really< small, disabling STD will free up drive space equivalent to the amount of RAM in your laptop.

I see no benefit from disabling the shock sensor.

Enjoy your much faster MBP!


Depends on what type of SSD you have. Some SSDs have a TRIM facility built into the firmware of the SSD — Sandforce controllers in particular have this. The Samsung 830 series have in-built garbage collection which renders TRIM unnecessary.

I have a Samsung 830 and have not modified a single thing. Runs great.