CNET logo Why You Can Trust CNET

Our expert, award-winning staff selects the products we cover and rigorously researches and tests our top picks. If you buy through our links, we may get a commission. Reviews ethics statement

Double your MacBook's storage with a tiny card called TarDisk

Tired of running out of storage space on your MacBook? TarDisk just might be the answer.

Jason Cipriani
Jason Cipriani
Jason Cipriani Contributing Writer, ZDNet
Jason Cipriani is based out of beautiful Colorado and has been covering mobile technology news and reviewing the latest gadgets for the last six years. His work can also be found on sister site CNET in the How To section, as well as across several more online publications.
Jason Cipriani
4 min read

When the hard drive on your MacBook is getting full, you have a few options: You can purchase an external hard drive and offload low-priority files to it; pick up an inexpensive USB drive; or take on the task or replacing internal storage yourself.

Or, there's TarDisk.

TarDisk is a small, SD card-like device that expands the storage of your MacBook. You pop it into your Mac's SD card slot, install some software and you're set. Once the setup is complete, TarDisk acts just like onboard storage.

The basics


TarDisk is available for the MacBook Air, MacBook Pro with Retina display, and older MacBook Pros.

The 128 GB TarDisk is available for $149, £103 or AU$202 or 256 GB for $399, £276 or AU$542. It's one of the more expensive storage solutions you'll find when searching, but you're also paying for the Pear software that comes with TarDisk.


When you first slide a TarDisk into the SD reader on a MacBook, it's treated just like any other SD card. OS X views TarDisk as any other external storage volume, where you can store files or even use it as a Time Machine Backup destination.

The other option -- and the reason you pay so much for TarDisk -- is to "Pear" the card with your Mac's internal drive. Meaning, your Mac will treat TarDisk as additional onboard storage.

So if your MacBook has 128GB of onboard SSD storage and you add the 256 GB TarDisk, OS X will combine the two into one 384GB hard drive. You don't have to worry about where a file is stored, or remember which drive to you created a folder on -- it's all the same.


Naturally, when you're using software to alter the way OS X interacts with storage drives, there's going to be a few things you'll need to be aware of:

  • Apple's Boot Camp won't work with Pear. You'll need to remove any Boot Camp partitions.
  • Pairing a TarDisk to your Mac should be viewed as a permanent solution. You can unpair a TarDisk, but the process requires restoring your MacBook from a Time Machine backup you've stored on a separate external hard drive.
  • A MacBook with OS X 10.10.2 or higher is required.

Then there's the form factor. Since TarDisk sits flush in the SD card slot -- perhaps even a bit inside -- installing it feels a bit permanent, so if you use the SD card slot often, this might not be the best solution for you. Otherwise, you can always use an SD card reader.

Prepping to Pear

You'll need to complete some prep work before you pair TarDisk to your Mac. Complete instructions can be found on the TarDisk website here, or on the instruction sheet included with your TarDisk.

Prep work includes creating a Time Machine backup, disabling FileVault and disabling any antivirus applications. You'll also need to disconnect and remove any external hard drives or USB flash storage currently connected to your MacBook.

TarDisk Verify Disk.jpg
Enlarge Image
TarDisk Verify Disk.jpg
Jason Cipriani/CNET

Then you'll need to verify that your current hard drive is working properly.

You can do this by booting into single-user mode by holding in Command-S as your MacBook powers on. Once lines of text begin scrolling across the screen, release the two keys. When the command prompt shows up, enter "fsck -fy" without the quotes and press Enter. Finally, enter that command again and let it run. If the command prompt states your volume "appears to be OK," type "reboot" and press Enter.

Log in to your user account, then quit all open programs. Next, open the Disk Utility app. You can find it in Applications > Utilities. Select your hard drive and click on First Aid or Verify.

If the utility finds errors on the disk, click Repair Disk and repeat the steps until there are no errors found.

Pairing the TarDisk

With the prep work out of the way, you're 95 percent done and all that's left to do is pair the TarDisk.

Insert the TarDisk into your MacBook's SD reader. Open Finder, and select the TarDisk drive. You'll find the Pear Installer application on the drive -- open it. Follow the prompts in the app, including checking boxes to indicate you have a current Time Machine backup.

Enlarge Image
Screenshot by Jason Cipriani/CNET

When presented with the above screen, move your mouse between the two icons. When Pear is highlighted, you'll see how much space your hard drive will read after Pearing. Highlighting the hard drive icon will show you how much space you currently use on your hard drive.

Click on Pear, then Continue.

The speed of the pairing will vary depending on your MacBook, how much data is on your SSD, processing power, and other variables -- but it should be completed in under 10 minutes. On the demo MacBook I used to Pear with a TarDisk, the actual "Pearing" process took under five minutes.

Enlarge Image
Screenshot by Jason Cipriani/CNET

Reboot your MacBook when prompted, and then bask in the glory of all that extra space you have now.