Western Digital’s SiliconEdge Blue is an internal solid-state drive (SSD) in a 2.5-inch form factor. SSDs have no moving parts, making them less susceptible to hardware problems. They are also fast when compared to standard hard drives. Unfortunately, SSDs are also very expensive and limited in terms of capacity when compared to hard drives.

To see how the SiliconEdge performs, we installed it into an easily upgradeable, late 2008 Unibody MacBook with a 2.4GHz Core 2 Duo processor and 2GB of RAM. We ran a series of tests on the MacBook’s internal 5400-rpm, 2.5-inch Toshiba hard drive to serve as a baseline before running the tests on the SSD drive. We also ran the same tests on a 7200-rpm, 320GB WD Scorpio Black drive, to serve as another point of reference—a faster drive than the standard internal drive, but much less expensive than an SSD.

Our testing showed the SiliconEdge Blue to be much faster than either of the hard drives we tested. The SiliconEdge Blue duplicated a 1GB folder 52 percent faster than the 7200-rpm Scorpio Black drive. The SiliconEdge Blue uncompressed a 2GB file 22 percent faster, launched Photoshop 40 percent faster, and booted up 11 percent faster than the Scorpio Black. Though impressive, these scores were not the fastest we’ve seen.

After hearing reports of performance degradation over time with SSDs in general, we decided to run another set of tests using Mac Performance Guide’s DiskTester application. The application includes a Fill Disk test that, as its name implies, fills the target drive with small files until it reaches capacity. The software tracks the read and write speeds of the drive throughout the process and includes an average speed result at the end of the task. We ran this test and took note of the results—an impressive 223MB per second for reads and 149MB per second for writes. For comparison’s sake, the 7200-rpm Scorpio Black drive averaged 51MB per second for reads and 62MB per second for writes.

We then followed a script used by Mac Performance Guide to “season” the drives, by erasing, filling, erasing, cloning a system to it, erasing, filling and erasing the drive once more before installing our test system back on the drive and running the Fill Disk test again. While some drives that we’ve tested (the OCZ Vertex and Crucial M225, for example) did indeed suffer from dramatic performance degradation after the seasoning, the SiliconEdge maintained its same, speedy write times and lost only 3MB per second in the read results. The Scorpio Black drive also reported nearly identical results post seasoning.

SSDs have a finite number of times each block can be written to, so technologies like wear-leveling are important to keeping the drive performing well over time. The SiliconEdge appears to handle the stress of continued use quite well.

Macworld’s buying advice

SSDs offer a significant performance increase over standard rotating drives, but at price out of reach of most consumers. Until prices come down and capacities go up, they will continue to be niche products meant only for enterprise servers and the most demanding power users. And though the SiliconEdge Blue was fast and consistent over time, it wasn’t as fast (and it has a shorter warranty) as other SSDs we’ve tested.

[James Galbraith is Macworld’s lab director.]