Friday, 9 August 2013

Expanding Macbook Air disk space with SD cards

I’ve had my Macbook Air for over a year now (crazy how time flies) and I still love it. The only drawback really is the limited disk space - the price you pay for speedy flash storage. This would not be a problem were it not for the fact that I have accumulated a lot of photos and music over the years - far too much for the 128GB disk space.

Initially, I tried to get around this by having all my music on my MacBook but keeping photos on external media. This had two problems: (1) by the time that Apps etc. are included, iTunes was still cramping my space, and (2) it was inconvenient to keep plugging in external media every time I wanted to play with my photos, which, given their state of disorganisation at the time, was quite a lot! The problem was compounded further by iPhoto, which is an horrendous space-waster but useful with Photostream.

Plan 2 was to move my iTunes library to an external hard drive that I could plug in when syncing my iOS devices but otherwise not really worry about. This freed up lots of space for sorting out photos (though not all of them), which in turn allowed me to clean up and delete most of my iPhoto library in favour of using Picasa, which is altogether much more sensible in the way that it organises (and shares) pictures.

The problem with Plan 2, however, was that it made it really incovenient to listen to music/podcasts etc. and even to manipulate playlists and things if I was not entirely stably situated - not to mention the use of a USB port keeping the drive attached.

The obvious solution, which I had considered for a while but delayed due to cost, was to get an SD card big enough for my iTunes library and use this instead. As the picture above shows, SD cards do still stick out a little and so they do not provide the perfect permanent disk expansion that I first envisaged when I got my MacBook - I tried out a 32GB for a while - but they are considerably more securely attached than a portable hard drive, much easier to carry around and free up the USB ports for other things. I got myself a SanDisk Ultra 64GB SDXC card for about £40 and moved my iTunes library onto it. This is clearly more per GB than an external hard drive but pretty reasonable for the convenience - and it is convenient. Access times are pretty speedy and you can go for the Extreme SDXC card if such things worry you.

So far, it’s working out really well and I can heartily recommend it if you have similar Macbook Air storage issues. My only real fear is misplacing the SD card because it is so much smaller than a portable hard drive! As an added bonus, the Mac mini that I have just ordered for work has an SD slot too, so I’ll be able to take my whole library to work if I want to without having to use up valuable HD space on such frivolities! (In fact, it's worked so well that I’ve also ordered a 128GB card for working on both computers, which seems much more convenient (and faster) than using USB devices for the same purpose.)


  1. First world problems Richard.

    A mini for work though, it's a contentious choice for the floor, but it's your field.

    Our guys use massive towers/Pros

    1. I'm not complaining. The Mac mini seemed to have the right combination of (semi-)mobility for my upcoming travels and power enough for my needs. I'll find out for sure when I get it of course - I use a Linux box or Supercomputer for any big number-crunching anyway.

  2. Hello,
    I just came across this and as I'm in a similar boat thought I'd let you know what I did...

    Temporarily - 64gb data traveler Kingston Micro usb flashdrive - $38 usd and it's tiny. Uses a usb though..

    Later - SDXC card as you mentioned earlier - along with a Nifty adapter or something similar (I may make something - apparently a lot of the SD adapters can be chopped down to be flush with the Macbook slot). Idea being to leave it in the machine....

    If you format it using mac os extended then the card (or usb flash) will have a uuid. You can use these instructions to stop the uuid from mounting at startup or after sleep...

    then... if you buy a small utility called Mountain from the Apple App Store - it's about $2 or so you can see the usb or ddxc drive and mount it with a single click whenever you need to access it..

    Advantage being you reduce the power draw of the added component and can leave it in for long periods.

    Just thought I'd share. For what it's worth I liked your site so much it prompted me to!


    1. Thanks, Raj, that's interesting. I did not realise that an SD card drew much power. Having a micro-SD with cut-down adaptor is an interesting idea - assuming that you can get it out again!

  3. Hey Richard,

    I am curious how you like your Air for doing bioinformatics. I am thinking to get an Air (I currently have a MacBook Pro but it is government issued and I have to return it). Does the Air handle large(ish) datasets well?

    Thank you!

    1. That's a good question, Katie, and might warrant a blog post in itself. The short answer is that it depends how large(ish) the data are, how/where you will be working, and how IO-intensive your work is. The MacBook Air seems to have similar grunt to the Pro (depending on specs, obviously) and I have used it for running some stuff, using SD or portable HD for larger data.

      I have just got myself a MacBook Pro with Retina Display, though, because ultimately the space issue does become a bit limiting for doing work on the go. (And the higher resolution of the Retina Display is better for coding.) If you have the budget, I'd recommend that. If you need to save money, can work on a stable surface with a HD plugged in and/or have SSH access to another system for most serious number crunching, a MacBook Air is probably fine.

  4. Good day Richard, I am thinking of doing this as well. May I ask if you had to prepare the SD card in any way before moving your iTunes Library? Did you format it to Mac OS Extended (Journaled) or just use it as is out of the package? Thanks in advance for any input. :-)

    1. Sorry about the slow reply. I had a look and I have it formatted to "Mac OS Extended (Case-sensitive, Journaled)". I'm not sure whether that is strictly necessary, though.

  5. I have a 2012 Macbook Pro and am having the same problem even though I have a 500GB Solid State Drive. I solved the problem when I installed a PNY 128GB StorEDGE Flash Memory Expansion Module I purchased on Amazon. Formatted for storage I actually have 129.44GB of storage, which I believe would solve the problems discussed here. It cost about $80 and is almost flush to the side of my Macbook Pro, even more flush than the 32GB USB Micro Flash Drive I have been using. The problem with a USB flash drive is that is not permanent storage as is the PNY storge I just installed. I believe this is the best bang for the buck.


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