Recondition an SSD on the Mac… for free!

Posted by on Jun 21, 2010 in Mac Specific, Technology | 10 Comments

As I mentioned a long, long time ago on this site, I upgraded my 17″ MacBook Pro with a Corsair 128GB SSD. The speed was astounding… for the first 5-6 months. Then things started to slow down. It started to get obvious when I was working on numerous video and photo files at the same time – like 30 or 40 files going at once. I chalked it up to a bottleneck in some part of the hardware and hoped that a reboot, a PRAM reset or even some Onyx action would solve the issue and the speeds would go back to normal. This worked a little here and there, but as time went by, the SSD just got slower and slower. A few weeks back, I got fed up with the SSD; it had become just as slow as a standard platter hard drive. That’s sacrilege in the SSD world. My own beloved SSD had become the enemy of my productivity.

To combat my new nemesis, I searched the Google and found the most promising article at this website here. I read with excitement until I clicked on the link for the software – it’s a paid app called DiskTester… and not a cheap one at $40.

The free option…

I believe there’s always a free way to get what you need, so I began racking my brain. It occurred to me – OS X has Disk built in. Duh! It can create volumes of very specific sizes, which seems to be the same function DiskTester is performing when it’s running its “recondition” option.

Here’s what I did:

  • used CarbonCopyCloner to clone my SSD to a nice 1TB drive on a Firewire 800 dock.
  • booted from the external drive into my clone OS.
  • opened Disk Utility and selected the SSD.
    • ran the “erase” function on the SSD.
    • ran the partition function – selecting 1 partition for the volume scheme.
    • repeated the partition with 16 partitions
    • reduced the drive back to one Mac OS Extended Journaled partition.
  • erased free space on the drive (seems unnecessary in retrospect)
  • clicked on the “New Image” icon at the top of Disk Utility’s screen. I selected the SSD as the target volume and made a DMG file to the size of the SSD itself, 128.04GB. Disk Utility created the image and the SSD was left with about 21.61MB remaining. I repeated the action with a 21.6MB image file on the SSD. This left the SSD with only a few KB of empty space. Sufficient.
  • insterted the OS X Snow Leopard DVD in my MacBook Pro and rebooted to the installation DVD. I ran the OS X setup as a new computer, not using the CarbonCopyCloner image. I figured a fresh installation would eliminate any detritus from tons and tons of use. I was right. The fresh copy was much better.
  • during the Snow Leopard installation process, I opted to import settings, apps, emails and documents from the 1TB clone. OS X put everything in perfect order for me. My work environment was back to the way it had started.

The entire process took about 90 minutes. I got it done during two episodes of Castle.

Here are some pics:

So what happened?

The Disk Utility-reconditioned SSD was indeed much faster than before the whole process. Boot times were almost back to day-1 speeds, applications opened super fast and I was able to get back to hard core production.

One caveat - I learned that the SSD should not be used as a target disk for bittorrent files or for other apps that intentionally create highly fragmented files. Literally hundreds or thousands of files downloaded in countless tiny fragments simply screw the SSD sideways. It just can’t handle that kind of intentionally fragmented data, not in that kind of volume. So now I use an external 1TB drive for my bittorrent and other downloads. The SSD seems way better off without that constant pounding.

Hopefully my sharing this with you folks helps a little. You may opt to buy DiskTester for $40 (I’m not saying you shouldn’t – I’m sure it has TONS of useful features and all with shining merit), but if you’re like me, you may want a free option that does a similar, if not nearly identical function. As an old friend used to say, “Free is the best price.”


  1. Milan Dandukovic
    July 18, 2010


    FINALLY someone posts a decent article on how to recondition an SSD on a mac. I’ve searched for months to find something like this… all in vain until now.

    You said that “Erase Free Space” function seemed unimportant, as you created as image File the size of the SSD. The “Erase Free Space” function does this as well. It fills the SSD, then deletes the file.
    I erased the SSD, then used “Erase free space”, installed fresh OS and found out, that SSD fragmentation was basically gone (using TechTool Pro, the free space was in one big chunk – before the “Erasing free Space” it was fragmented as hell).

    Does this mean, that if I basically just partition the SSD and then use “Erase Free Space” on it, I recondition my SSD?

  2. JasonTomczak
    July 18, 2010

    Thanks for the info, Milan! If Erase Free Space really does the same thing for SSD health, then all the other partition/dmg steps can just be ignored. Of course, writing zeros to a 128GB drive is way, way slower than making a drive-sized disk image, but it reduces the whole project down to three major steps:

    clone master drive using CCC
    – boot from external/cloned drive
    open Disk, select master drive and Erase Free Space (write zeros once)
    – get a good night’s sleep while zeros are written
    – insert Snow Leopard DVD and reboot the computer to the DVD (and unplug your external cloned drive for data safety)
    install Snow Leopard and import files and applications from the external clone.

    Hopefully that works just as well for other folks out there.

  3. Milan Dandukovic
    July 19, 2010


    thanks for your quick reply!

    I am not sure if writing 0 on the entire SSD does actually improve performance (actually I believe it degrades it). You can write 0′s on the SSD using Disk Utility, but in my case I found out, that it didn’t improve any speeds.
    However after erasing my SSD with “Erase Free Space” button, I did find my speeds improving a little. I have a Samsung SSD 220MB Read / 200MB Write speed. The problem is, I do not know how fast the SSD actually was after I had bought it, but right now its on 200MB Read / 150MB Write, which I find to be OK.

    Lastly, here is a link to fragmentation image of my SSD after erasing free space (before it was fragmented as hell – note that I did not defrag my SSD, I only erased it and then erased free space on it):

    Hope it helps!

  4. Derek Stutsman
    September 6, 2010

    These techniques didn’t work for me, but I found something that did:

    - boot from Snow Leopard disk, run disk utility
    - back up the drive to a disk image on an external drive
    - boot off an ubuntu 10.4 cd and install it
    - download hdparm and run the included script
    - boot from Snow Leopard and run disk utility again
    - restore the backup image to the drive

    Pain, but it worked flawlessly. My performance is again like new.!

  5. Anton
    October 5, 2011

    Ha! That was a clever move I placed everything related to Torrent on 2nd HDD rather than SSD. Like why would I ever need all that drive speed for just downloads? The only thing I’m worried about is Photoshop scratch files with can grow unto 60GB in minutes. Do you think Mac Os X Lion’s available Trim feature would avoid that problem?

  6. AJX
    March 24, 2012

    I know i’m way too late … but i think you forgot something about formatting the SSD into GUID partition map

  7. Pedro
    January 14, 2013

    You inspired me with your techniques, specially by limitating DL to a proper HDD.
    For reconditionning my SSD, I used Time Machine on it to backup it to an external disk, rebooted using the Install DVD to launch Disk utility and ran several “Erase with secure option”, then I finally reinstalled the Backup using Time machine with The Install Disk.
    It seams to hav worked quite well according to Xbench.
    Done in about the same time, but I erased like 4-5 times the disk.

  8. Alan
    February 9, 2013

    This procedure worked! My SSD suddenly slowed down to a crawl, and going through these steps seems to have restored it back to health! Genius! Thanks!

  9. Michael
    October 20, 2013

    I moved everything like movies and music to my network hard drive. I use WD Live to store big files and keep my MakBook SSD clean

  10. jasontomczak
    October 27, 2013

    Sounds like a good setup. =)

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