The Mercury Elite-AL Pro Dual mini, Other World Computing’s newest portable storage device, is a RAID array that zoomed through our Photoshop test and recorded impressive speed in our other tests.

While the Mercury Elite-AL Pro Dual mini’s name seems complicated, its appearance is anything but. Aside from small holes in the front plate, various interface connections in the back, and the company’s name in brushed aluminum on top, the array looks like a simple block of aluminum with rounded edges. The drive comes with USB 2.0, FireWire 400 and 800, and eSATA. OWC also includes an owner’s manual, a CD with various freeware and shareware, a FireWire 800 cable, a USB 2.0 cable, an eSATA cable, and a FireWire 800 to 12-Volt power cable.

A curious omission came when we found that the Mercury Elite-AL Pro Dual mini doesn’t come with an AC adapter. While the array is bus-powered through FireWire, it requires additional power when using an USB or eSATA connection. You can use the FireWire 800 to 12-Volt power cable if you have a MacBook Pro, but if you have a laptop that doesn’t have a FireWire port, such as the current MacBook or MacBook Air, you’re out of luck unless you order an AC power adapter from OWC.

Macworld Lab tested a Mercury Elite-AL Pro Dual mini that shipped with two Hitachi 320GB 7200-rpm hard drives as a RAID 0, totaling 640GB of capacity. The drive is available in a variety of storage capacities and either as RAID 0 or 1. Changing the array configuration after you’ve bought the drive is a little difficult to do, since there were no instructions in the included manual. However, OWC does provide an Assembly Manual on the Web that explains how to do it.

In our testing the Mercury Elite-AL Pro Dual mini posted excellent numbers in our USB 2.0 and FireWire 800 tests. The RAID 0 version scored an AJA write high of 32.0MBps using USB, tying the Buffalo MiniStation Metro ( ). It then broke all of our FireWire read records, getting 77.9MBps in our 2GB folder test, 88.6MBps in the 2GB file test, and 84.9MBps in the AJA test.

Where the Mercury Elite-AL Pro Dual mini really impressed us was in our low-memory Photoshop test, placing the best scores of any drive we’ve tested this year. With USB, it took anywhere from 63 seconds in RAID 0 to 64 seconds in RAID 1, while other drives took 65 seconds or more. Using FireWire 800, the time went to 45 seconds in RAID 1, to 43 seconds in RAID 0, a Lab high, or low we should say, more impressive considering other drives we’ve tested over the same protocol took an average of more than 50 seconds. If Photoshop were a steep mountain, the Mercury Elite-AL Pro Dual would make a reliable climbing partner.

Macworld’s buying advice

Boasting excellent Photoshop scores and first-rate transfer speeds, the Mercury Elite-AL Pro Dual mini overall is an excellent choice as a storage device for demanding users.

[Editor's note: Updated 6/29/11 to clarify the availablity of an Assembly Manual on OWC's website to change array configurations.]