Mach Xtreme advertises the drive with the insane speeds of 170 MB/s read and 185 MB/s write; benchmarks they achieved with ATTO. Unfortunately, we are unable to reproduce these numbers. This does not mean that the achieved results are any less impressive. With ATTO, we hit 162 MB/s read and an incredible 130 MB/s write. The drive really manages to flex its muscles because of its SLC memory.
In HD Tach, we are able to replicate the read performance, but get rather erratic write speeds. The MX_ES ends up with an average of 130 MB/s write because the drive fluctuates between 160 MB/s and a mere 20MB/s write. A consistent line would have been much better since its really low dips may or may not be noticeable in real world usage.
In comparison to other USB 3.0 drive, the Mach Xtreme is not quite the fastest reading drive, as it ends up behind a Patriot and Lexar drive, but plays in its own league when it comes to write performance. It is almost 50 MB/s faster than the next drive - all due to the SLC within.
USB 2.0 performance testing produced similar looking lines in HDTach, but the MX-ES still manages to use the aging interface properly by pretty much filling up all available bandwith completely.