Updating Samsung 840 EVO SSDs

On a Mac with the Performance Restoration Tool

Posted by Matthias Schmidt on January 12, 2015

Samsung found an issue with their SSD 840 EVO Series that dramatically reduces the I/O Performance for old files. They created a new firmware to fix the problem. Unfortunatelly there is no easy-to-run-updater for Mac OS X. Instead they provide the Performance Restoration Software as an ISO file which also rewrites all data after applying the update to get things back to speed.

The new firmware EXT0CB6Q is not listed as such and only available through the Performance Restoration Software. So even while fresh SSD wouldn’t need the restoration process this is the only way to update them on OS X (or Linux btw.).

I couldn’t get the software to boot from a USB stick at first but with a little help from a small Windows tool I got around this. But then I had to learn that the tool doesn’t work while FileVault is enabled. So I disabled it, waited a few hours for the decryption process to finish and tried again. Just to learn the tool doesn’t work when there is a second disk connected. So I had to disconnect the 2nd drive.


  1. Make sure your time machine backup is up to date. Just in case.

  2. If used, disable FileVault and wait for the decryption process to finish.

  3. Unplug all other disks but the one you’d like to update.

  4. Get access to Windows somehow (Virtual Windows works fine).

  5. Download the Performance Restoration Software ISO.

  6. Download Rufus from rufus.akeo.ie.

  7. Use Rufus with default settings to put the downloaded ISO on a USB stick.

Update Process

  1. Make sure your Mac is plugged into the wall if it’s a laptop.

  2. Start your Mac with the USB stick plugged in and hold down the alt key while it boots.

  3. Select the yellow USB icon called Windows.

  4. Select your target disk (most likely 0) and say yes to the warnings.

  5. Wait. Wait. Wait. This takes quite a long time depending on the amount of data you have stored on your disk.

  6. Don’t forget to re-enable FileVault.

Now enjoy your fast-again SSD. I know it’s a little annoying to use Windows to prepare the USB stick but hey at least it’s not nessecary to put the SSD in a Windows machine just to update the firmware!