Unfortunately, the one area where HDDs beat SSDs is price. SSDs cost many times per gigabyte of storage what HDDs cost, so it is unlikely that many users will be able to store all their data on an SSD alone.
The answer to this problem is to use two drives, an SSD and an HDD, ensuring the best of both worlds. Apple has made it possible to install two hard drives in a number of their computers, including the iMac (2010 and newer), Mac Pro, and Mac Mini. Mac portables also have a third party option for a second hard drive by removing the optical drive.
Once you’ve got your SSD purchased and installed, we’ll show you in the steps below how get your data sorted out; how to put “the big stuff” on your existing HDD and move OS X and your applications to the SSD, where they’ll see the most benefit.
Set Up an SSD Boot Drive with Your User Folder on an External Drive
Before we begin we’ll want to create a temporary user account to help us move things around safely and quickly. To do this, go to System Preferences > Users & Groups and click the lock icon in the lower left of the window, entering your password when requested.
With the panel unlocked, press the plus button to create a new user. Make the account an administrator and set a name of “Temp” and no password. Press “Create User” when done to finish up.
Next, we need to get the contents of your current drive onto your SSD. We can accomplish this by cloning. There are several excellent disk cloning utilities; for the purposes of this article we’ll use Carbon Copy Cloner.
Fire up the free cloning software and choose your current HDD as the source and your new SSD as the destination. Under “Items to be Copied,” check everything except your existing user folder within the “Users” disclosure triangle. Make sure that your temporary user account is selected.
Press “clone” and wait for the process to finish. The end result is that all your system data and applications will now be on the SSD, while your pictures, music, movies, and documents will remain on the HDD.
Now we need to tell OS X where your users folder is. Restart the Mac holding down the Option key until the boot menu appears. Select your SSD, which is now bootable thanks to our cloning process, and boot into OS X using the temporary user account.
Once the system has booted, go to System Preferences > Users & Groups and click the lock icon in the lower left of the window. Once the panel is unlocked, find your actual user account, as opposed to the temporary account you’re now using, in the menu on the left. Right-click (or Control-click) on the user account’s name and select “Advanced Options.”
Be careful in the Advanced Options screen and don’t change any parameters except for the ones outlined here. Changes to the entries on this screen can cause serious issues with your user account and may result in loss of data.
That said, next to the Home directory field, press “Choose.” In the window that pops up, navigate to your HDD, then Users, then your user account. Press “Open” when the account has been found, then “OK” to close the Advanced Options screen. Your user account is now linked to the location on the HDD.
Finally, it’s time for clean-up. Using the Finder, delete everything from the HDD except for the Users folder containing your user account. This will clear up room and make the drive non-bootable again, transforming it into a data storage drive.
Once all files are removed, empty the trash and reboot. As you reboot, before the computer makes the familiar Mac “chime,” hold down simultaneously the P, R, Command, and Option keys on your keyboard. Continue to hold them down until the computer reboots itself. Let go when you hear the second chime. This is called a PRAM reset, and it is necessary to tell the computer which hard drive to boot from (in this case, the SSD.)
Once your computer reboots after the PRAM reset, you should find yourself booted to the SSD with all your system files and applications, while your home folder resides on the HDD.
Set Up an SSD Boot Drive with Your iPhoto Data on an External Drive
Moving an iPhoto library is a fairly simple process, as Apple has built-in some tools to help us perform this task.
First, install your SSD and clone your entire drive except for the Users > [Your User Account] > Pictures folder. This will transfer all data from the HDD to the SSD, except for the Pictures folder, and make the SSD bootable.
Reboot the computer and perform a PRAM reset, described above. Once you’ve booted back into OS X from the SSD, go ahead and delete everything on the HDD except for your Pictures folder. Now, we need to tell iPhoto to look to the HDD instead of your home folder (now located on the SSD).
With iPhoto already closed, hold the Option key and open iPhoto. You’ll be presented with the iPhoto library chooser. If there is only one iPhoto library on the computer, it usually does a good job of auto-detecting it. You can tell if it has the right library by looking at the path displayed below the selection window.
If iPhoto chose wrong, simply press the “Choose” button and manually navigate to the iPhoto library on your HDD. Once you’ve selected it, iPhoto will load your existing library and you’ll be back to managing your photos right where you left off. The only difference is that your photo library is on the HDD and now has plenty of room to grow.
Set Up an SSD Boot Drive with Your iTunes Data on an External Drive
Setting up your iTunes library on an external drive is quite similar to the iPhoto steps above, with a few key differences. First, we want to make sure that all your iTunes content is in the iTunes Media folder. To do this, open iTunes and go to File > Library > Organize Library and check the box “Consolidate Files.” Press OK and wait for the process to finish. This step will copy all files that aren’t already there into the iTunes Media folder.
Next, open up Carbon Copy Cloner and, this time, select everything except Users > [Your User Account] > Music > iTunes > iTunes Media. This will transfer the entire contents of the drive except for your iTunes media files (i.e., the individual songs, movies, podcasts, etc.) from the HDD to the SSD and make the SSD bootable.
Once complete, reboot the computer, perform a PRAM reset as described above, and boot back into OS X. Open up iTunes and navigate to Preferences > Advanced. Next to the iTunes Media folder location box, press “Change” and point iTunes to the location of your iTunes Media folder on the HDD. This tells iTunes that, while the XML library file is still on the system drive (the SSD), the actual media files are on a different drive (the HDD).
Press OK to save changes and wait while iTunes updates the pointers between the local library and the external media. This may take a while depending on the size of your library. Once complete, you’ll have your iTunes library back up and running just as when you last left it.
All of the steps discussed here assume that the SSD being installed is too small to handle a one-to-one clone from the HDD. That’s why the instructions discuss leaving “the big stuff” such as music and photos on the HDD. If your SSD is big enough, it’s often easier to clone everything from the get go and then manually copy the “big stuff” to the HDD later on. The end result is the same.