Towards the beginning of the year, IBM released the Ultrastar 18ZX, an 18 gig drive that featured ten platters encased in a 1.6" chassis. As IBM's first 18 gig, 10k rpm unit, the 18ZX, though speedy, could not keep up when newer-generation units such as the Cheetah 18LP and the Quantum Atlas 10k arrived. IBM's designs always hit the market a bit before Seagate's, yet seemed to be a bit "primitive" in comparison.

An example would be the Ultrastar 18ZX, the competitor to the Seagate Cheetah 9LP. Though both designs featured 1.5 gigs/platter, the Cheetah both possessed a faster seek time and managed to cram its six platters into a design a mere 1" in height. The disparity widened even more when the Ultrastar 18ZX was compared to the Cheetah 18LP. Here, not only was the IBM's seek time lagging, the Cheetah packed 3 gigs per platter while Big Blue's offering placed a rather paltry 1.8 gigs/platter.

With the advent of Quantum's mighty Atlas 10k, the Ultrastar 18ZX has fallen even further behind. It's massive, unwieldy 1.6" design seemed to have been no more than a stop-gap measure, something IBM hastily put together simply to offer an 18 gig 10k rpm unit. And stopgap it was, for scarcely three months after the 18ZX started shipping en mass (a very short time when it comes to SCSI drives) Big Blue announced the Ultrastar 18ZX.

The Ultrastar 18LZX hit retail channels less than two months after it's initial announcement via press release. These days, such speed qualifies as blazing time-to-market. Witness, for instance, Western Digital's Enterprise 10k. Announced March 1st, it has yet to be seen nearly five months afterwards . IBM has finally released a drive on parity with competitors to present a worthy contender against the reigning champ.

This new challenger is special in a couple ways. It's the first drive, for example, to break the barrier of a 5 millisecond specified seek time. Its 4.9 millisecond seek time weights in as the fastest yet. Its five, 3 gigabyte platters are the first to feature glass rather than aluminum substrates. This "more advanced" material can be refined to a surface smoother than ever before, allowing data to be packed more densely than ever before while also being less subject to thermal expansion. Interestingly, the drive features only a two meg buffer. While doubling the cache found on the Cheetah 18LP and matching the Atlas 10k, the 18LZX actually takes a step backwards when compared to the 18ZX. Perhaps this is tacit admission that two megs is enough and yet more evidence that massive buffers do not conquer all. The unit tested here was an Ultra2 SCSI drive; Ultra160/m versions will also be available. An enterprise-standard 5-year warranty backs the drive.

Despite its impressive specifications and new technology, the Ultrastar 18LZX fails to keep up with the Quantum Atlas 10k. The Business Disk WinMark 99 run under Windows 95 reveals the IBM drive trailing the Quantum unit by 10%. The margin thins under NT, with Big Blue's disk trailing the Atlas by 7%. NT tests place the 18LZX behind the Atlas by 6% in the Business WinMark and by nearly 11% in the High-End.

Tests run under Adaptec ThreadMark display significantly widened margins. Here the Atlas blows away the Ultrastar, leading by margins of 39% and 27% respectively under Win95 and WinNT.

The human factors of the 18LZX are praiseworthy. Idle noise is quite inconspicuous. Seeks are obviously audible, as one would expect from a 4.9ms drive, but they're less objectionable than the Cheetah 18LP's, perhaps along the same level as the Atlas 10k. The unit runs quite warmly outside a drive cooler in our spacious testbed case but within parameters. A more cramped setup may warrant active cooling, however.

Overall, while speedier than the 18ZX, the Ultrastar 18LZX falls short of the lofty standards set by the Atlas 10k. The fact that IBM has finally closed the generation-gap between its drives and Seagate's when it comes to performance is overshadowed by the fact that neither drive delivers the performance of the Quantum unit. When it comes to a matchup between the IBM and Seagate, however, Big Blue pulls ahead by some modest margins. So, if for some reason you're dead-set against the Atlas 10k, the 18LZX is worth consideration. Otherwise, go for the Atlas 10k: It's still the performance champ.