External hard drives have evolved in the last year--and not just in terms of increased capacity. Drive makers have finally realized that Macs and PCs handle the same data types and that building separate drives for the two platforms isn't financially smart or helpful to users, who are dealing with ever-increasing amounts of data. As a result, vendors are rolling out drives standardized on the USB 2.0, FireWire 400, and FireWire 800 interfaces.

Three of the latest are Iomega's Triple Interface Professional Silver Series Desktop Hard Drive, Western Digital's MyBook Pro Edition II, and Maxtor's OneTouch III, Turbo Edition. While these units don't represent every variety of external drive, they do characterize the genre quite well.

For example, the 750-Gbyte Iomega, while smallest of the three in both size and capacity, is no slouch--it's a single-drive unit in a world where 500 Gbytes in a box was pushing both heat and capacity boundaries last year. The Maxtor and Western Digital units offer, respectively, dual 750-Gbyte drives for a 1.5-terabyte capacity and dual 500-Gbyte drives for a 1-terabyte capacity; both are enclosed RAID boxes. All of the drives are intelligent enough to power down when not in use--a good thing, since prolonged usage will make them warm to the touch. All three use EMC's Retrospect Express backup software, which offers automated backup and can create a disaster recovery strategy.

Iomega's Silver Wins Gold For Speed

	Triple Interface Professional Silver Series
	Company: Iomega
	Price: $450
	Recommendation: Great drive, fastest of the group overall, but two 500-Gbyte models will give you more capacity for less cost.

The Triple Interface Professional Silver Series Desktop Hard Drive is the smallest and has the lowest capacity (750 Gbytes, or 698 Gbytes formatted) of the three drives. Iomega's offering is a single-drive unit and doesn't require the extra overhead of the RAID drives.

Glance at the specs, though, and you might think Iomega's drive couldn't possibly measure up--while most 750-Gbyte drives selling in this range have 16-Mbyte data buffers, the Silver only offers an 8-Mbyte buffer. However, it's the fastest of the three drives tested when using a USB connection and only slightly slower than the Maxtor drive using a FireWire 400 connection.

Of course, when you take into account even the small operational overhead added to Maxtor's and Western Digital's drives as they incorporate RAID into the configuration, it's obvious that, with less to do before it starts to read or write, Iomega's baby box couldn't help but be speedy in comparison.

There's really no installation for this drive other than to load Retrospect Express. Iomega advertises the unit as "buttonless backup," and that's true. It doesn't have a one-touch backup button, but with Retrospect's ability to perform scheduled or immediate backups from the keyboard, I'd question whether a button is needed.

Because it's petite, the Silver can be used in either horizontal or vertical orientation. It has rubber feet for flat operation and includes a small plastic stand should you want to hoist it on its side. Grooves on the case lock the stand in place.

There are also 1-terabyte ($675) and 500-Gbyte ($270) Silver versions. At those prices, a pair of Iomega Silver drives could give you 1 terabyte of storage for significantly less than a single 1-terabyte drive.