Upgrading the SSD in a mid-2012 Macbook Air

The time has come for me to expand the storage space on my mid-2012 Macbook Air, which comes with only a 128GB SSD and 4GB of RAM. With the SSD divided into two partitions, Windows and Mac, of 64GB each and a dual-boot configuration using rEFIt boot manager, I was left with less than 5GB of free space on the SSD after installing applications that are necessary for my development work (Visual Studio, xCode, Netbeans, MySQL). Short of buying a new laptop, my only recourse is to take apart the Macbook Air and manually upgrade the SSD.

Before you continue, make sure to backup your data. You can use Time Machine to backup your OS X partition or Clonezilla to backup both the OS X and Windows partitions at the same time.

Taking it apart

To take apart the laptop, you will need a P5 pentalobe screwdriver. I got mine from eBay for $1:

Contrary to what Apple may tell you, with the correct screwdriver, taking apart the Macbook Air is a breeze. The following photo shows the laptop with the cover removed. The red rectangle is where the SSD was originally connected:

And this is the original 128GB SSD chipset, a THNSNH128G8NT made by Toshiba:

Upgrading the SSD

Now it’s time to find the replacement SSD that has 256GB of storage space. Again, eBay is the best place to search for these kinds of things. I managed to purchase the following module for just 125 USD:

It is clear from the label that the storage module is not originally intended for the Macbook Air. And with the tape used to secure the connection, I have doubt whether the replacement will work as intended. However, the item description, albeit in poor English, showed me that the seller really knows what he is selling:

In short, the notice tells the user to purchase the correct type of SSD for his Macbook Air as Macbook Air 2010/2011 (model A1369/A1370) and Macbook Air 2012 (model A1465/1466) have different SSD interface standards. The different specifications for the SSD connectors are also explained in details. I therefore decided to purchase this SSD to give it a try.

This is the Macbook Air with the 256GB SSD installed:

With the new SSD installed, I was expecting the need to reinstall Mac/Windows on the laptop before it can be used. But guess what, this SSD comes with Yosemite pre-installed and Mac OS could boot up just fine:

However, the account password is not known and I needed to follow the instructions here to reset the password. With the password reset, I was able to check that the new SSD is indeed 256GB:

Success! The Macbook Air SSD has been upgraded to 256GB and the OS to Yosemite without any hassle.

But wait a minute, how about the old SSD? Can we make use of it? The answer is yes – you simply need an adapter. One can be purchased for a cheap price from eBay, just make sure that it is intended for your MacBook Air model. I purchased this from eBay for just $5:

With the adapter, the old SSD can be used as a 128GB SATA hard disk. Due to the slightly different form factor compared with a normal 2.5″ SATA hard disk, you may have some difficulties using the adapter on devices with limited physical space (Mac Mini, USB enclosure or laptop). In my case, I decided to use the old SSD on my desktop computer and it works without issues.

Migrating your data

Unless you prefer to setup your dual-boot configuration on the new SSD again, you will now want to restore the backups that you have made prior to the upgrade onto the new drive. If you prefer to start with a clean configuration, I do not recommend using the Yosemite version that comes with the drive for security reasons. Instead, boot into the Recovery menu and choose to reinstall OS X.

As always, backing up and restoring data with a dual-boot configuration on any Mac systems is tricky. The steps which I recommend are as follows:

1. Backup the OS X partition on the old SSD using Time Machine
2. Backup the Windows partition using Clonezilla
3. Restore OS X onto the new SSD using Time Machine
4. In Disk Utility, create a new partition for Windows and restore the original Windows partition onto this partition using using Clonezilla
5. Finally, install a boot manager such as rEFIt or rEFInd. Do not use Bootcamp – it’s pathetic having to hold down the Option key just to boot to Windows.

Take note that rEFIt would not work with Yosemite due to the introduction of the ESP partition not known to rEFIt, which still attempts to install the bootloader code to the EFI partition. You will need to use rEFInd, an actively-maintained development fork of rEFIt instead. Follow this guide to install rEFInd and read here for some useful tips and tricks with rEFInd.