The My Book Mirror Edition is preformatted in NTFS and works right way when hooked to a Windows computer. It also works with Macs, but you will need to reformat it into OS X's file system, HFS+, which is a simple process.
Cost per gigabyte
Most direct-attached external drives are single-drive models, so the cost-per-gigabyte comparisons here aren't exactly apples-to-apples. When viewed against single-drive units from Maxtor, SimpleTech, and Vox, however, plus a 2-drive and a huge 4-drive 2TB enclosure from LaCie, you can see that the 2TB My Book Mirror Edition offers a very compelling value at 21 cents per gigabyte. We have not reviewed the LaCie 2big Dual drive, but it should be noted that if offers eSATA in addtion to USB 2.0. Even when you factor in that you get roughly half that capacity when using the default RAID 1 configuration, the My Book Mirror's cost-per-gigabyte figure doubles to 42 cents, which is still very competitive.
|Model||Capacity||Est. street price||Cost per GB|
|WD My Book Mirror Edition||2TB||$420||$0.21|
|LaCie 2big Dual||2TB||$510||$0.26|
|Maxtor OneTouch 4 Plus||250GB||$90||$0.36|
Considering that we ran our tests using the My Book Mirror's default RAID 1 configuration, which detracts from performance as data is written to two hard drives simultaneously, the My Book Mirror Edition performed well in CNET Labs' testing. It registered 138.4Mbps on our write test and 156.8Mbps on our read test.
It's a little hard to put its performance in proper perspective since the My Book Mirror is the first multibay external hard drive we've tested that has features only a USB 2.0 connection. The LaCie Biggest, for example, also comes with FireWire 800. The My Book Mirror Edition was significantly faster than the LaCie when operating via USB 2.0, but it trailed behind most single-drive USB 2.0 external hard drives--but only by a small margin.
Throughout testing, during heavy and lengthy workloads, the My Book Mirror Edition remained very cool and quiet. This is a double blessing, not only reducing the noise in your home or office but also giving you some peace of mind that the drives aren't running hot to where they could overheat.
(Longer bars indicate better performance)
Service and support
Western Digital backs the My Book Mirror Edition with a generous three-year warranty. Though this is not as good as the five-year warranty provided with the My Passport Studio, it's a lot better than the stingy one-year warranty found in many other storage devices such as the SimpleTech (re)drive. You won't need much support for the drive, but Western Digital's technical toll-free phone support is available from 6 a.m. to 5 p.m. PT Monday through Thursday and from 6 a.m. to 3 p.m. Friday through Sunday. On its Web site, you will find a comprehensive set of Web-based support including downloads, product RMA, a sizable knowledge base, and online installation guide.