The Asus CRW-5224A external CD-RW drive ($150 street) is about as compact as this type of drive can get. It does use an external power brick instead of an internal supply, though, so moving the unit from one location to another is a bit less convenient. And the 480-Mbps maximum transfer rate imposed by USB 2.0 also reduces the convenience of an external drive somewhat. Still, the drive fared surprisingly well on most tests. CPU utilization is always a concern when using USB 2.0 as a storage interface, and CD WinBench 99 2.0 reported a utilization of 3.78 percent—substantially higher than any ATAPI-based internal drive. Typical ATAPI internal drives run less than 1 percent, but 3.78 percent is still pretty low, and shouldn't affect system performance substantially.

Since this drive plugs into a USB port, installation is a snap, although the drive works best with Microsoft Windows Me and XP. You'll need updated drivers for Windows 98 SE and the latest service pack for Windows 2000.

In the CD-RW burn tests, the CRW-5224A posted test scores similar to those of the other drives; apparently, 24X CD-RW writing doesn't saturate USB 2.0 in the same way that high-speed CD-R writing does. The Plextor PlexWriter Premium burned rewritable discs slightly faster, but it's also rated to burn at 32X versus the 24X max speeds of the other drives.

Asus provides one CD-R and one CD-RW disc, a USB 2.0 cable, and the popular disc-burning application, Nero Burning ROM 5.5. You'll also find a bracket that lets the drive stand vertically to save space. At $150, the Asus CRW-5224A is the costliest drive in our roundup, but the convenience of an external unit makes up a bit for the price disparity.