Just before the latest MacBook Pro updates were released, rumors swirled that the new models would adopt solid-state drives in addition to hard disk drives and drop internal DVD drives. That sounded perfect to me, so I made it happen even though Apple didn’t. Here’s how.

OWC SSD Data Doubler

Just before the latest MacBook Pro updates were released, rumors swirled that the new models would adopt solid-state drives (SSD) in addition to hard disk drives (HDD) and drop internal optical DVD drives across the line. That sounded perfect to me. As I dove for the couch cushions in search of spare change to add to my computer upgrade fund, I considered that I didn’t really need a new computer. What I wanted was SSD. But SSD tech is expensive — really expensive if I wanted the same amount of storage offered by my MacBook Pro’s HDD. Luckily, there’s a way to have both. Inspired by others, I decided to remove my optical drive and install an SSD in its place and pair it with a large hard drive.

Advantages of Paired Storage

I love this setup. I have the blazing fast speed of the SSD (it really does feel like getting a new computer) and I have enough room for everything I need thanks to the spacious HDD. There are some other advantages that might not be obvious at first glance, too:

  • You can install an alternate system on the HDD. I have Snow Leopard installed on the SSD for everyday work and I have Lion installed on the hard drive for testing.
  • You can use Boot Camp to install Windows on the HDD because it is a true internal drive. Boot Camp won’t work with an external drive, but it works great with this setup and it doesn’t use any of the space on the precious SSD.
  • I have lots of room for Virtual Machines on the 500GB HDD so I can create other testing setups as needed.

Yes, I have to connect an external optical drive every time I need to install something from disc, but once I was done with the initial setup I haven’t needed it that much. It really has proved to be the perfect arrangement  for my needs. Here’s how you can do it with your own MacBook.

The tools. Click to enlgarge.

What to Order

Sizing Things Up

To get the space requirements for your SSD, select your drive and “Get Info” to see how much space is used (make sure to empty the trash first!). Now check how much space is being used by the User folder(s) on your computer. The difference between the two is all the system files and applications that you will want to put on the SSD. The Users folders themselves can go on the HDD.

As an example, I was using about 300 GB on my HDD. The Applications (including CS5 and Xcode), root Library and System folders take up about 53 GB of space. My Home folder takes up about 240 GB (and my iTunes Media is on a network share). I wanted enough room for my system files and applications on the SSD, and some room left over for a portion of my user files so that these frequently used files would benefit from the speed of the SSD.

Picking the Right SSD

Using my computer as an example, I could conceivably get by with a 60GB SSD (I have 53 GB of system and application files, as mentioned). But that’s cutting it too close for the system files (OS X needs 4-5 GB of free space just for temp files and such things). And it would mean that all user files would have to go on the HDD. On top of that, early reports indicate that SSDs benefit from extra free space to keep them running fast. In my case, that would mean at least 80 GB. I wanted to get a drive from the high-performing OWC Mercury Pro line, so I moved up to the next available size of 115GB. If you’re struggling with the decision, it’s always a good idea to buy as much storage as you can afford.

Removing the Optical Drive

I have held various certifications in Apple hardware repair starting back in 1994, but I honestly didn’t need any of that training to upgrade my mid-2009 MacBook Pro. Any uni-body MacBook or MacBook Pro is pretty easy to get into. iFixit.com is a great resource for a detailed photo walk-through of the steps to remove the optical drive from your Mac. I placed the optical drive in an external slim USB enclosure so I could continue to use it, and I also have an external Blu-ray drive for any DVDs or CDs that I might need.

I also removed my existing hard drive, placing it in an external enclosure, and installed a new 500 GB 7200RPM drive from Seagate in its place. You might choose to stick with your computer’s existing HDD, depending on your storage needs.

The bracket for your SSD. Click to enlarge.

Installing the SSD

The next step is to attach the SSD to the bracket, after which you can install the bracket itself where the optical drive used to be. As I mentioned above, I bought the SSD and the bracket in a bundle from OWC. They helpfully include the tools that you need and provide online video guides for the installation.

The inside of the MacBook with the SSD installed. Click to enlarge.

Configuring the System

Setting up your new drives in Disk Utility. Click to enlarge.

I decided to do a clean install of the system to the SSD and then copy over select files from my user folder. I booted from the OS X installation disc (I actually have an external FireWire 800 hard drive set up for this purpose – saves 20-30 minutes), formatted both drives with Disk Utility and ran the installer. When that was done, I booted to the SSD, ran the guided setup, Software Update, and installed my core applications.

Handling Users and Home Folders

There are a couple of choices here. I could move my entire user folder to the HDD, but I wanted the benefits of the SSD for some frequently used files from the Home folder. I decided on a mixed solution where I could keep some user folders on the SSD (~/Applications, ~/Desktop, ~/Library in particular) and the folders with hefty storage requirements (Documents, Downloads, Movies, and Pictures) on the HDD. I kept the ~/Music folder on the SSD so that iTunes would be able to quickly load the iTunes Library file, which is the index to all of the media files and the associated metadata like ratings and play count. I had previously set the preferences in iTunes to point the iTunes Media Folder location to a network share, so all of my media files are actually on a network share. I suspect that most people would want to keep their ~/Music folder on the SSD and use the advanced preferences tab in iTunes to move the iTunes Media Folder to the hard drive.

I copied the old Documents, Downloads, Pictures and Movies folders from my original HDD (now installed in an external enclosure) to their new home on the big internal hard drive. Once I had them in place, I was ready to fix up my Home folder.


The trick to splitting up your Home folder so that some stays on the SSD and some points to the HDD is to use symlinks. Symlinks are a function of the UNIX underpinnings of OS X to create something like an alias, but at a low-level in the filesystem. I created links to point certain directories in my Home folder to locations on the HDD. After creating the links, those folders appear to be in the “normal” spot in my Home folder, but they don’t use any room on the SSD as they act like an alias that points to the HDD. Even thought the image below shows “Alias” as the kind for these link files, don’t make the mistake of creating an alias in the Finder. You will need to use the command line to create a symlink.

Bottom Line

This new setup has everything I need. Incredible boot times, fast application launching, and overall snappy performance. I have a triple-boot system with Snow Leopard, the developer preview of Lion, and Windows 7, with room for a few Virtual Machines too. Now that the Mac App Store is taking off, I don’t even have to hook up the optical drive very often. It’s beautiful.

If you’ve done something similar, I would love to hear about it. If you want to try this setup and have questions, I’ll try to answer in the comments below.

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  1. Weldon- can you comment on two things, 1. is battery life any better or worse? and 2. is heat build up any better or worse? Thanks for the article.

    1. Battery life is better, as you would expect with SSD. I didn’t mention this explicitly, but most of my work happens in a web browser or a text editor. Since the apps and my user cache are on the SSD, the HDD only gets used intermittently. It doesn’t use much power just waiting.

      The machine is generally cooler because of the SSD, but it will heat up a bit from Time Machine or heavy CPU use.

  2. what about time-machine? does it back up both drives?

    1. Yes, Time Machine (and CrashPlan+) back up both internal drives.

  3. What about time-machine? Does it back up both physical drives?

  4. Dave Treadwell Friday, April 1, 2011

    I’ve done a similar thing, however with a standard HDD.

    A quick search on a well known auction site for “Optibay” will give you the Caddy for ~£10/$15.

    Great to double your macbook’s memory in the space of 15 minutes!

    1. I bought the same stuff from OWC as well, just that I have 2 x OWC 200GB SSD with RAID 0.

      Tried getting the Optibay Caddy for my unibody, but it doesn’t fit well and I dump it.

  5. Hi Weldon! Thanks for a very good post! I just installed a 120 gb SSD and a 500 gb seagate hybrid hd with 8 gb SSD in my brand new 2011 mbp 15″. Ive installed snow leopard on the SSD and I’m ready to set up my home folder but then I read this post about how smart you linked it all instead of just pointing to the home folder via account options. However, I’m not good enough in terminal to do this. Can you help me through the process? Can you send me an email so you maybe can help me on iChat? Maybe even via screen sharing? Please drop me an email. Thank you! /Mattias

  6. Thanks for this. I’m certainly tempted, especially with the idea of using an enclosure for the old optical drive, whenever I need to load something by disk.

    What I’m curious about is what the exterior of the machine looks like when all of this converting is done? Do you still have a CD-sized slot on the right side of the machine, or is that filled in at all? Are you likely to trick somebody into trying to shove a DVD into your Macbook if you’re so inclined?

    1. There is a “brush” on the opening to the optical drive which is attached to the inside of the unibody enclosure. When you remove the optical drive, this piece is left in place. The outside of the MacBook Pro looks exactly the same. If you tried to insert a CD, you would bump up against the bracket just behind this brush.

  7. what are the disadvantages/advantages to putting the ssd in the main bay and hdd in the optical drive bay and vice versa?

    1. There is no real difference to OS X. However, from a hardware perspective, the HDD bay is designed with rubber grommets and some separation from the unibody case to minimize vibration. The cooling system is also designed to vent heat from the HDD in that bay. The optical drive can obviously produce some heat under heavy use, but this is generally infrequent and short-lived. I don’t have any evidence or empirical testing to support my decision, but I felt safer putting the HDD in the main bay and the relatively cool SSD in the optical bay.

  8. For those who have Macbook Pros with ExpressCard slot can get an ExpressCard slot insertable SSD.

    I have this kind of setup for a 15months now (http://ingus.tunt.lv/index.php?zoomzina=1029) and i can assure you – it is best of the three worlds – i have speed, i have space, i have superdrive. And also the setup is super simple:
    1) insert the drive
    2) clone the system (except Movies, Pictures, Music)
    3) reboot

    Additional advantages are the super simple doc protection if you leave it unattended (or in a hotel) – just pull the ssd out and put it in your wallet (it is small). If something happens to your computer (had to change the video card on mine) you can attach the ssd to any intel based mac via USB and work on (if you create on that computer a user like yours, then delete the user folder, then create a symlink to your user folder on ssd, you don’t even have to reboot the donor computer – just switch the users and rock on) :)

    1. Sounds like a great setup, Boo.

  9. Mitch Malone Friday, April 1, 2011

    Does doing this void your warranty? I have a brand new MacBook Pro i5 and I don’t want to void the warranty if that is the case.

    1. Opening the case does not void your warranty. Damaging something while you have the case open will void your warranty, so be careful.

      Further, the Genius Bar will generally not work on your machine with non-stock components installed. You may have to return the machine to the state it was in when you bought it to get service under AppleCare.

  10. For a slip second I forgot this got posted on Fools’ Day :)

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