OWC Mercury On-The-Go (500GB)

Laptop hard-drive capacity hit the 500GB mark just a few months ago. The OWC Mercury On-The-Go is an external version of this new breed of 2.5-inch hard drives. Aside from having the largest storage capacity among compact external drives, the Mercury offers a handful of other features. The drive supports USB 2.0, FireWire 400, and FireWire 800, and it performed very well in our tests. Its design offers some geek aesthetic with a clear plastic casing that lets you see the internal hard drive and the circuit board. Even though the drive is not the most compact among its peers, its capacity, good performance, and versatile connections justify its $350 price (which translates into about .7 dollar per GB).

Design and features
The OWC Mercury On-The-Go ships in a very simple package that includes a travel pouch, a software CD, data cables, and a power adapter. According to OWC, the power adapter is required for all connection types except FireWire 800; however, we found out that it is only necessary when you use the drive with USB 1.1. We tried the drive with several computers that have USB 2.0 or FireWire and never had to use the adaptor.

The software CD contains NovaStor NovaBackup (for Windows) and ProSoft Data Backup (for Mac OS X). These backup applications work well, but if you are looking for something more advanced and easier to use, we'd recommend Acronis True Image. There's also another application for Mac users on the CD called Intech Hard Disk SpeedTools--a nifty utility that can do several disk-related operations, such as defragmentation, benchmarking, integrity check, and so on.

The drive's design is also very simple. Its transparent casing shows the internals of the unit. On the back of the drive, there are two FireWire ports, a mini USB port, the power port, and the power switch. The power switch is hard to reach. On the front, the drive doesn't have any LED lights; however, the internal hard drive (seen through the clear case) indicates power and operation status with a blinking blue light. At the base of the drive, inside the casing, OWC put a large piece of aluminum that helps to dissipate heat generated by the hard drive. However, it makes the device a bit heavier than it looks. The Mercury is actually not too bulky and heavy; it just weighs about 10 percent more than the Iomega eGo, but the transparent casing creates a size and weight illusion--enough to surprise you when you pick up the drive. The drive's fanless aluminum heat sink helps the drive perform quietly and stay cool during operation.

Like most external hard drives, the Mercury is a simple plug-and-play device. However, the Mercury doesn't come preformatted and will need to be formatted before it can be used. The drive works with both Macs and PCs. As FAT32--the only format that can read and write to both platforms--doesn't support the Mercury's storage capacity, you'll need to format the drive in either NTFS (Windows) or HFS+ (Mac OS X). Windows and Mac OS X will work with you through the formatting process in a few simple steps.

Performance
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.

Portable hard drive read/write tests (in Mbps via USB 2.0)
(Longer bars indicate better performance)

Write

Read

OWC Mercury On-The-Go

138.5 

162.6 

Iomega eGo

72.7 

158.2 

Toshiba USB 2.0 Portable HDD

77.1 

152.7 

Maxtor OneTouch4 Mini

140.2 

151.8 

See pricing