Building a cheap external SSD: USB 3 or Thunderbolt? 2 – USB 3

In the first article, I set out to get the best value for my money in assembling an external SSD using a cheap Crucial MX300, costing me under £0.15 per GB, and described the Thunderbolt case, costing a total of £120 – more than the SSD itself.

USB 3 case

As I was going to compare this against such an expensive Thunderbolt option, I spared no expense in the bundled acronyms, although I am not quite sure what difference they really make. I went for the Inateck top-of-the-range model for a grand total of £14.99. I could have saved another £ or two if I had been prepared to go for fewer acronyms, but at this price I felt every letter counted.


This is what you get for so little: a compact snap-together plastic case, a handy rectangle of stick-on padding, and a short USB 3 cable. There are no instructions, but unless you get seriously inventive, there is only one way to mount your SSD in the case.


The SSD slides in to mate with the connectors, the cover slides over, and snaps shut. As promised, no tools are needed, and my extremely myopic wife could do this without her spectacles.


The Inateck cases have no optional external power supply: there is just the USB 3 port, an on/off switch, and a comforting status light.

I simply connected the enclosure to my iMac using the supplied cable, turned the drive on, and there it was mounted on the Desktop.

Case comparisons


You do get what you pay for. The Delock is relatively expensive, larger, and considerably more robust. The Inateck is cheap, more compact, and probably wouldn’t enjoy getting walked on.


This view of their business ends shows well the differences in case size and finish.

In use

There is one big difference between the functionality of USB 3 and Thunderbolt drives in OS X: S.M.A.R.T. monitoring. For reasons known only to Apple, OS X – even El Capitan – does not support S.M.A.R.T. over USB, even USB 3. This is a design choice on Apple’s part, as there is a free kernel extension which will enable S.M.A.R.T. monitoring over USB, and Thunderbolt drives enjoy full S.M.A.R.T. support.


Fire up DriveDx with the SSD in a Thunderbolt case, and you get full information and all the health indicators supported. The Crucial SSD in a Delock case is really good here, with a full set of information about the drive.


In comparison, the limited general information given by the Crucial SSD in the Inateck case is of little value, and tells you nothing about drive health, unless you are prepared to install the kernel extension.

Otherwise, there seemed little difference between my Thunderbolt SSD costing £230, and the USB 3 version for a mere £125.

In the next and concluding article I will look at performance test results.