Why You Can Trust CNET Western Digital My Book Mirror Edition review: Western Digital My Book Mirror Edition
Western Digital My Book Mirror Edition
The Western Digital My Book Mirror Edition is a USB 2.0, two-drive external storage device that can be used in either RAID 1 for data security or as a single volume in RAID 0 to take advantage of the full capacity of its two drives. Preconfigured in RAID 1, the My Book Mirror is not intended for high throughput performance, but we found its read and writes speeds to be on par with other external hard drives--including non-RAID and single-volume hard drives. The are two versions of the My Book Mirror Edition: a $289 1TB model and a $499 2TB model. In its default RAID 1 configuration, however, you will get roughly half the storage capacity since your data is written to each drive. We reviewed the 2TB version, which can be found for as little as $399 online at the time of this writing. We recommend either My Book Mirror Edition drive if you are looking for a simple and secure direct-attached storage solution.
The Good
The Bad
The Bottom Line
| Drive type | External hard drive |
| Connector options | USB 2.0 |
| Available capacities | 1TB, 2TB |
| Capacity of test unit | 2TB (roughly 1TB in its default RAID 1 configuration) |
| Drive speed | 7,200rpm |
| Cache | 16MB |
| Dimensions (LWH) | 6.1x3.9x6.5 inches |
| Notable design features | User-replaceable hard drives |
| OSes supported | Windows 2K, XP, Vista, Mac OS X |
| Software included | WD Backup Anywhere and 30-day trial of Mionet |
| Service and Support | 3-year warranty |
Design and features
The WD My Book Mirror Edition looks good, with its sleek black casing and curved corners. If the single-drive My Book Essential or Home Editions look like a hard cover book, the My Book Mirror resembles War and Peace at nearly 4 inches thick. Though it's relatively compact for a two-bay enclosure, its power adapter is bulky, which makes the whole package a little less portable than it could be.
The drive has an LED on the front that changes color with the drive's status: powered on, in use, idle, and error. On the back, you will find a power connector, a low profile USB 2.0 port (similar to one found in pocket-size external hard drives), and a power switch button. There're no FireWire or eSATA connections, which is disappointing but understandable as the drive is preconfigured with RAID 1--which is optimized not for speed but data protection. (The company's pricier My Book Studio drives add FireWire 800 and eSATA interfaces.) In RAID 1, the 2TB My Book Mirror Edition provides roughly one terabyte of capacity. The benefit is if one of the hard drives dies, you just need to replace it, and there's no data loss or usage interruption during the process.
You can change the hard drives into a RAID 0 configuration and get the most storage space out of it, but then the data will be more vulnerable to corruption (if just one of the two drives fail, you'll lose all your data). However, you can't set up the two drives as two separate volumes, where the status and data integrity of one drive has nothing to do with that of the other.
We really like the fact that the internal hard drives are user-replaceable. You don't even need tools replace them. Though it's not obvious, you simply press on a spot in the middle of the My Book Mirror's top front edge and the cover will pop open giving you access to the drives. The My Book Mirror uses standard 3.5-inch SATA hard drives, but there's a catch--you can only use Western Digital hard drives. While this limits the device's flexibility, it's not really a problem as WD hard drives are popular and sold for relatively competitive prices.
The My Book Mirror Edition comes with two USB 2.0 cables of different lengths--5 inches and 2 inches--to accommodate where you want to put it. This is a nice gesture as we have run into drives that don't come with enough cables.
The drive also ships with a full version of WD Backup Anywhere and a 30-day trial of Mionet for remote access. WD Backup Anywhere is a wizard-driven backup solution that allows for backing up your selected data to any other media, even onto your iPod. We tried it out, and it worked as intended. It's important to note that the serial key (required to make the software work in nontrial mode) is printed at a corner on the back of the setup instructions poster--a very obscure place.
We also tried out the Mionet service and that worked well too. We were able to access the hard drive's content over the Internet and drag its folders and files onto a local computer. As the drive is not a NAS device, the host computer has to be on and is connected to the Internet for this to happen. After 30 days, Mionet will cost you $8 a month or $80 a year.
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 |
| SimpleTech (re)drive | 500GB | $140 | $0.28 |
| Vox V1 | 750GB | $235 | $0.31 |
| Maxtor OneTouch 4 Plus | 250GB | $90 | $0.36 |
| LaCie Biggest | 2TB | $1,300 | $0.65 |
Performance
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)
 | Write | | Read |
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.