Gigabyte X58A-UD3R: USB 3.0, SATA 6G

We've started with HD Tach—while the program is almost certainly on its way out, it's still useful for comparing read performance between the various drives we're testing. Since HD Tach can only compare performance between two drives at a time, the top graph is USB 3 vs. USB 2, while the bottom graph is USB 3 vs. eSATA.

USB 2 vs. USB 3 Read Performance. 

USB 3 vs. eSATA

These performance results are as encouraging as anyone could ask for. The 7200.4 Momentus hard drive inside the BlackArmor isn't a high performance drive by desktop standards, but its read performance triples when we move to USB 3. If we toss out the random dip  in read performance, eSATA and USB 3 are almost identical, with the edge apparently going to USB 3. eSATA's burst read speeds are about 15 percent higher, however, probably due to the native interface's lower latency. We don't know for certain if USB 3 can keep pace with eSATA when comparing faster drives yet, but as far as mass market external enclosures are concerned, it's a non-issue—and a fabulous performance improvement over its predecessor.

Our next stop is SiSoft Sandra 2009 and that application's suite of hard drive tests. Sandra also reports the random access times and full stroke times in milliseconds. 

Again, we see an advantage for eSATA when it comes to full stroke and random access speeds but read speeds are identical for both of the two high-speed standards.

Based on what we've seen here, it's time to wave goodbye to USB 2. Depending on what you need from an external storage solution, it may even be worthwhile to replace a USB 2 enclosure with a USB 3-capable one and add USB 3 support via a PCI Express card. USB 2's bandwidth is capable of handling simple desktop tasks, including streaming 1080P video smoothly, but you'll definitely notice the difference if you spend any amount of time shifting data from Point A to B.