The OWC Mercury On-The-Go performed very well on our tests. We tested the drive with all of its connections: USB 2.0, FireWire 400, and FireWire 800. On our USB 2.0 read and write tests, the Mercury topped the chart among pocket-size portable external hard drives, though all read speeds were grouped tightly together. We saw more of a variance with write speeds, where the Mercury and Maxtor OneTouch 4 Mini were nearly twice as fast as competing models from Iomega and Toshiba.
When we switched to FireWire 400 and FireWire 800, the Mercury's write speeds increased significantly to 181.9Mbps and 189.9Mbps, respectively. We expected throughput to increase with the move to FireWire, but we were surprised to find so little difference between FireWire 400 and 800. Similarly, we saw read speeds increase when moving from USB 2.0 to FireWire 400 and 800 (194.62Mbps and 197.2Mbps, respectively), but again the difference between FireWire 400 and 800 was very small.
Service and support
The Mercury On-The-Go is backed with a one-year warranty from OWC, but the internal hard drive, Hitachi TravelStar 5K500, has a separate warranty from Hitachi for an additional two years, so you have a total of a three-year warranty on the hard drive itself. During the time of OWC's warranty, you are advised not to tamper with the casing of the drive, which would void the warranty.
You can get support from OWC via live chat, phone, e-mail, and fax. Live chat is available on its Web site weekdays from 5 a.m. to 8 p.m. PT, and from 8 a.m. to 2 p.m. on weekends. The toll-free technical support line is available weekdays from 6 a.m. to 6 p.m. and 7 a.m. to 2 p.m. on Saturdays.
(Longer bars indicate better performance)