Two Solid State Drives (SSD) in a MacBook Pro

Posted by on Apr 10, 2011 in Mac Specific, Technology | 13 Comments

This is how I set up two Solid State Drives (SSD) in my 17″ MacBook Pro.

For the last year or so, I’ve been struggling with the storage limitations of my 128GB SSD drive. With my professional photography, photos of my baby girls and client files alone, I was sorely lacking hard drive space. Distributing files across several external drives worked for a little while, but then just got too complex. Nothing sucks worse than having to sort through several external drives to find a photo when you’re on a deadline.

To solve my storage dilemma, I decided to add a second SSD drive to my MacBook Pro. I decided against adding a standard spinning hard drive because of the draw it would take on my battery – that and the heartbreaking drop in performance if I was editing massive photos from the standard drive.

I know OWC sells very nice internal 2.5″ drive bays for the MacBook Pro. They run about $75. There are other companies that sell similar drive bays for $90-ish. I found one on eBay for about $30 with shipping. It’s generic and not as pretty as the OWC version, but it fits and works fine.

For the second drive, I bought the Mushkin Enhanced Callisto Deluxe 240GB drive from It had the best ratings at the time, and it was hard to argue with 285MBs/275MBs read & write times.

These photos show the progression from single drive + DVD to dual SSD with no DVD.

Removing the screws from the MacBook Pro. The first time is slow – maybe 2-3 minutes. I can get in and out of the MBP case now in under 60 seconds.

This is the original 128GB Corsair P128 Solid State Drive I bought in 2009. It was running slowly due to outdated firmware and no effing firmware tool for Mac systems. I had to pull the drive, clone it to another drive, pop it in a Dell laptop to run the firmware update (which erased the drive) and then re-clone my data back. After the firmware update, the drive ran almost as fast as the day I bought it.

From the Department of Obvious Statements: the Mushkin SSD is exactly the same size as the Corsair drive. Same size, same weight.

To employ the second drive in the MacBook Pro, you need to pull the SuperDrive out of its snuggly, warm spot near the logicboard. Note: with your MBP case open, find yourself a can of compressed air and blow out the fans. You’ll see that mine were a little nasty. Clean fans = cool, fast laptop.

Be super careful removing the screws and the paper-thin SATA cable (the orange tab just to the right of the SuperDrive).

Once the SuperDrive has been removed, you can buy an external adapter to continue using it to read/write DVDs. External adapters cost about $20. Personally, I’m over the 8X speed and went with a 22X drive. More on that later.

Next, the secondary SSD is placed in the new drive bay. It fits very snugly and the drive height seemed about 1/2mm too much, but once the drive & bay were inserted into the SuperDrive spot, it fit perfectly. Oh, and don’t forget to put the little SATA cable back in place on the logicboard.

Here’s the P128 SSD in the drive bay, in the SuperDrive slot. And 8GB RAM from newegg. Twas $600 when it first came out, then $300 last summer. I got mine for $120 in November 2010. Last week, I saw it on sale for under $70. Good lordy, how prices change.

Here’s where I cloned the P128 with my OS X and files over to the new Mushkin 240GB SSD. Cloning SSD to SSD is pretty fast – roughly 2GB/minute.

Once the cloning is done and MacBook Pro is rebooted, I wiped the old drive clean for use as storage.

Lessons from using Dual SSDs in the MacBook Pro:
Lesson 1: Using the 240GB drive as the primary was a rookie mistake. I think I was tired (twins up all night) and not thinking right. The 128GB SSD should have been the primary with the 240GB used for all that fantastic, high-speed storage, scratch disk, etc. (Now I remember – the Mushkin drive was about 60MB/s faster than the Corsair and served better as the main drive.)
Lesson 2: FTLOG, OMG, keep a daily backup routine. Even though Solid State Drives like the Muskin Calisto 240GB have a MTBF (Mean Time Before Failure) rating of 2 million hours, you never know when it’s going to just puke on you and die. Unlike platter drives, SSD drives are very, very difficult to recover data from. My Mushkin drive died in under 30 days. Completely unresponsive. Not even visible connected to an external drive dock. Just friking dead. Gone. Toast. Mushkin said it happens to 1 in 1,000 drives, cannot be anticipated, prevented or recovered from.
Lesson 3: Again, backup to TimeMachine, Dropbox, Mozy, ZumoDrive, or whatever external, off-drive solution you like best; just make sure you do it daily. I use all four of those options concurrently. 50GB with Mozy, 2GB with Dropbox, 3GB with ZumoDrive and a 2TB FireWire 800 drive for TimeMachine.
Lesson 4: The potential of an SSD failure is not related to dual-drive action but just the facts of life in the hard drive world. You may get the 2 million hours of use from your drive (roughly 228 years – good luck testing that out!) but you also may get 20,000 hours, or just 200. A note in fairness – my Corsair P128 SSD has never had an issue and has been running strong, 20 hours per day, since June 2009.
Lesson 5: Running dual SSDs in a MacBook Pro is really quite awesome. To have extra storage, a super fast scratch disk, etc. is simply beautiful. If your MBP is out of warranty and/or you don’t mind risking warranty repairs, and if you don’t need to burn DVDs while on the road, then the dual SSD setup could work well for you.


  1. haventfoundme
    January 7, 2012

    Any testing done with the battery life? I’m interested in knowing how much this has on the battery and how often you find yourself charging the battery.

  2. JasonTomczak
    January 7, 2012

    HFM – While I had the dual SSD setup, I found that the battery life was only reduced by about 10-15 minutes per charge. I was still able to run at least 5-7 hours per charge (40% brightness). Of course, it depends on what you’re doing on the laptop, but the second SSD really doesn’t produce any drag.

  3. Nick
    February 14, 2012

    Hi Jason,

    Great article. Thanks! Any instructions on how to set up the software side of things. I want to drop a ~250gb SSD in my optical bay as a boot/scratch disk and get a new 750GB internal drive for storage/working library. How do you set this up?

  4. @ngel
    March 11, 2012

    Whats the black material you’ve covered the top of the caddy with?

  5. derpy
    April 12, 2012

    @ @ngel, guessing it´s the “bottom” side of the caddy

  6. MISHOX Michal Svec
    June 13, 2012

    Can you backup these two SSD drives automaticly on one TimeMachine Drive? How do you do it?

  7. Jason Tomczak
    June 13, 2012


    Yes – Time Machine should automatically back up any internal drives as long as you haven’t specifically told it not to back up a volume or folder. On my MacBook Pro and 2011 27″ iMac, both with dual drives, Time Machine keeps both the boot/app drive and content drives backed up perfectly.

    In short, you should be fine. =)


  8. jasontomczak
    June 13, 2012


    Yes – Time Machine should automatically back up any internal drives as long as you haven’t specifically told it not to back up a volume or folder. On my MacBook Pro and 2011 27″ iMac, both with dual drives, Time Machine keeps both the boot/app drive and content drives backed up perfectly.

    In short, you should be fine. =)


  9. Josie
    November 3, 2012

    I’ve upgraded my 2012 2.6 15″ mbp from a Crucial M4 256GB and 7200rpm 750GB HDD in the optibay (noisy!), to two ssd’s. Now I have a Samsung 830 512GB in the optibay.

    Was planning on setting the 830 as bootdisk, but for some reasons this gave boot and shutdown problems (like waiting 30sec for the bootchime and hanging after shutdown in bootcamp). Because of this I would recommend the Crucial M4, same read speeds and slower writes but you won’t notice it in real life, and for me it worked perfectly from day one.

    Switched back to M4 as bootdrive and the 830 in the optibay (my mbp doesn’t like booting from the optibay) and it flies!

    Everything about the system is superfast AND totally quiet. Thanks to the Ivy Bridge processor the only time the fans com up is when playing games.

    Even with two ssd’s battery life improved quite a bit. I got over 6 hours with browsing, watching hours of tv shows in flash and silverlight, playing HD video in VLC, launching all apps at once. I even played a couple of minutes of Batman: Arkham Asylum.

    I think with only browsing and some other light tasks it could last for 10 hours, maybe even more.

    M4 and 830 cost: €200 and €350, that’s €550 and definitely not cheap. But apple’s own 512gb ssd option would set me back €915, and now i have a ‘free’ spare 750GB hdd in an usb 3 enclosure for Time Machine backups.

  10. Timothy
    February 15, 2013

    Hey i wanted to know if you can tell a difference in performance between 1 ssd or dual ssd in a computer without raid. Do you need to raid dual ssd to see the performance over a single ssd?

  11. jasontomczak
    February 16, 2013

    Hi Timothy – you’ll find that running dual SSDs in JBOD will be no faster or slower than a single SSD. It’ll be more responsive than having an SSD boot and HDD data drive setup, but as for SSD boot and SSD data, no speed difference. SSD in RAID, however, can give good increase in speed, but it depends on the SSD drives you plan to use, the RAID controller, etc. You’ll probably also lose Trim. Personally, I think RAID0 is binary Russian roulette. I would never use it under any circumstances (but that’s just me).

  12. Jeremy
    October 2, 2013

    Hi, I’ve read somewhere that there might be some problems about reliability in using SATA III (6G) drives into the Optibay of MBP 17.

    Did you do something special to solve this issue?


  13. jasontomczak
    October 6, 2013

    I never had any issue with using SATA III in the second drive bay in the 17″ MBP. It could be a firmware problem with the drive itself (like firmware is too old). Make sure your MBP is fully updated for firmware and OS X updates as well.

    The only drive related issue I have ever run into is one of my 2010 15″ MacBook Pros simply did not like 1TB drives, whether SATA II or SATA III, whether in the main drive bay or secondary. 750GB drives worked flawlessly in either bay. Go figure!

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