Taken from : http://www.macnn.com/reviews/mercury-on-the-go-pro-ssd-storage.html

Mercury On-The-Go Pro SSD Storage

October 15th, 2009
SSD storage will surprise you.

Solid-State Drives, unlike regular external magnetic hard drives, have no moving parts, because they use a form of flash memory for storage. The Mercury SSD drive comes in the same clear hard plastic case as the hard disk-based Mercury products, but when you hook the drive up to your computer, things are a bit different. Other World Computing has added Solid-State Drive (SSD) storage to their Mercury portable hard disk product line. The Mercury On-The-Go SSD comes in 64 GB, as reviewed here, 128 GB, and 256 GB sizes, with prices of $299.99, $479.99, and $799.99, respectively. They come with the drive, a set of cables, including FireWire 800, USB2, and a FireWire 800 to 400 adapter, and a soft carrying case.



OWC SSD Package Contents

SSD Background

Solid-State Drives, unlike regular external magnetic hard drives, have no moving parts, because they use a form of flash memory for storage. You can think of them as an USB stick on steroids. The use of flash memory instead of a hard drive is still rather new, which accounts for the steep entry price. Solid-state drives allow for faster data access, energy efficient operation, wider temperature operating range, and theoretically better data reliability. Unlike hard disk storage, we don’t have years of use to measure its theoretical reliability. Some sources claim that SSD drives degrade over time faster than a hard disk-based drive. For more technical information on SSD drives, you can read the Wikipedia article. A good article for comparison on hard drive life by David Morgenstern appears in eWeek.

Mercury On-The-Go Pro 64GB SSD

The Mercury SSD drive comes in the same clear hard plastic case as the hard disk-based Mercury products, but when you hook the drive up to your computer, things are a bit different. In the first place, it is completely silent. No fan, no spindle noise, no access "scritch scritch" that we are all familiar with from hard disks. Secondly, if you are used to slow portable USB drives; this will be a very pleasant surprise. The Mercury SSD drive is not only faster than a laptop drive; it is faster than the fastest desktop drive I have: A Seagate Barracuda 7200.11 1.5 TB, which is housed in another OWC external case.



OWC SSD Drive Bottom


Speed Tests

I used a 750 MB disk image for testing. I copied it from the internal disk to the external disk, and then mounted the disk via double-clicking on it. The following chart compares my Seagate hard drive (HDD) and the OWC SSD using FireWire 800 and USB2 using a stopwatch to time the operations.

Speed Test - Times in Seconds
Copying Mounting
SSD via FW800 12.1 15.9
SSD via USB2 24.1 28.0
HDD via FW800 12.5 16.0
HDD via USB2 25.0 28.0


To get a second opinion on these numbers, I ran XBench 1.3 to gather another set of performance numbers. In this test, I compared three drives: an internal 750 GB drive connected via SATA, the same external Seagate 7200.11 as before connected via FireWire 800, and the OWC SSD also connected via FireWire 800. I ran all tests on a 2009 Mac Pro. The internal drive had an unfair advantage because it was connected via SATA, nevertheless, the SSD was faster than both of the hard disks. In the table, higher numbers are better.

SSD Seagate 7200.11 Internal disk
  (FW800)   (FW800)   (SATA)
Overall Score 138.87 42.92 76.65
Sequential read (4K blocks) 20.86 MB/sec 8.63 MB/sec 34.43 MB/sec
Sequential write (4K blocks) 69.03 MB/sec 68.34 MB/sec 81.86 MB/sec
Random read (4k blocks) 14.55 MB/sec 0.47 MB/sec 0.66 MB/sec
Random write (4k blocks) 9.38 MB/sec 1.26 MB/sec 2.02 MB/sec

Hardware

The back of the unit contains plugs for four connectors: two FireWire 800, USB2, power, and an on/off switch. I'm a bit confused by the on/off switch, since you can just unplug the unit from the computer to turn it off, and there's no disk to spin down. There is no FW400 connector; for those who want to connect the SSD to an older machine, OWC includes a FW800 to FW400 adapter cable in the package. This bus-powered drive needs no power adapter, but if you plan to use it as a startup drive, MacNN recommends purchasing the $4.99 optional AC adapter.



OWC SSD Connectors


If you need this combination of speed, size, and durability, then the OWC On-The-Go SSD is a great choice. However, this combination comes at a high price. For slightly less money ($269.99 instead of $299.99), you can get a 750 GB portable hard disk in the same case from OWC, instead of the 64 GB SSD drive. On the other hand, the hard disk based product will be slower, noisier, more fragile, and consume more power. SSD is the better way to go, if low price and storage space are not high on your list of needs.


Edited SSD Explanation by Ilene Hoffman, Reviews Editor
Pros
Small and light.
Very fast - faster than my fastest hard disk.
Rugged.
3-year parts and labor limited warranty. Cons
Expensive.
Only available in small sizes at this time.