Design and Features
While USB flash drives all serve the same basic function -- data storage on a device no bigger than a small cigarette lighter -- each has a certain feature to distinguish it from the competition. With Lexar's JumpDrive Mercury, that distinguishing feature is an "E ink" meter, which shows you how much space is left on the drive in real-time -- even when it's not plugged in. At first this is little more than a novelty feature, but it soon becomes indispensable.
The Mercury features Lexar's answer to SanDisk's U3 platform, dubbed PowerToGo. PowerToGo is similar to U3 in that it transforms your USB key into a device that does much more than simply carrying data. With PowerToGo, you're able to store your favourite software applications (e-mail, Web browser, word processor, music playback software, etc) -- including all software and Windows preferences -- and launch them directly from the drive, on any Windows 2000, XP or Vista machine. This is done without modifying any files on the host PC whatsoever, and once you remove the USB key from the machine, all of your data leaves with you.
PowerToGo is bound to come in super-handy for those that use more than one computer on a regular basis, share a computer with other people or are using a machine without access to admin privileges. The last case is particularly poignant, as when you're on a machine without admin access you're unable to install any software whatsoever.
The range of applications that support PowerToGo is similar to the U3 list. Some are freeware, while others must be purchased after the trial period. There's quite an extensive list there, including Skype, Firefox, Thunderbird, Winamp and a huge variety of other apps such as RSS readers and password keepers. Once installed, the applications are accessed through the PowerToGo dashboard, which uses the familiar design of the Windows start menu.
We tested the 1GB (AU$74.95) model, but the Mercury also comes in a 2GB version which will set you back AU$134.95. These prices are more than reasonable when compared to SanDisk's offerings, whereby a 1GB drive costs around AU$15 extra.
Our performance tests involved recording read and write speeds using 32KB, 256KB, 2MB and 64MB files, which are typical of file sizes that are most often copied to flash drives. We recorded read/write speeds of 7221/219KBps, 9284/1310KBps, 9557/3140KB/sec and 9830/3277KB/sec respectively.
This makes it the slowest out of the four drives we tested (the Lexar JumpDrive Mercury, Lexar JumpDrive Lightning, SanDisk Cruzer Crossfire and SanDisk Cruzer Micro), both in terms of read and write speeds. However, in real-world terms we wouldn't describe the device as being "slow".
Finally, even though PowerToGo has applications running off the flash disk as opposed to the computer's hard disk, we didn't notice any tangible increase in latency.