If you peel apart an external HDD's casing, won't you see similar "converter" parts, anyways? One of my external USB HDDs failed on me and so I had to take it apart to run it as an internal from SATA. I imagine that I could probably use the old external parts to rig up some other drives through USB if I wanted -- the only difference being that it would be USB 2.0. So, the advantage here is USB 3.0, no? Buckiller and Schizofrog make good points, I think: Will these really old drives make much use of the higher transfer rate? Many of the HDDs on the market hit around a 1.5 gb/s transfer rate and use Sata II or III (I think?). Sata II can handle well above that rate, as can USB 3.0. So, again: is this really speeding anything up? It's just the convenience of jacking it in through USB as opposed to cracking your case and running it internally.