A little more than a year ago, shortly after StorageReview.com's inception, we received boatloads of e-mail requesting a review of IBM's newcomer, the Ultrastar 9ES. Even before our launch, it had garnered a reputation as a speedy drive combined with quiet operation and cool temperatures. When it finally entered the SR testbed, the drive lived up to its billing, delivering competent performance with pleasing aesthetics. Though the drive was edged out in performance by the Quantum Viking II, the Ultrastar 9ES was nonetheless a drive we could heartily recommend to a user searching for a great entry-level SCSI disk.

At the beginning of the year, Western Digital surprised the industry (well, they surprised us, at least) by being the first to hit the streets with a next-generation SCSI drive. Our look at the drive, now over two months old, proved that the new WD did indeed outperform the previous crop of disks- as it should have. For the first month or so, WD's Enterprise had no competition. Eventually, however, models from competing manufacturers finally started to hit the street. The first is the successor to the crowd-pleasing 9ES, the IBM Ultrastar 18ES.

Last year, IBM's drive lineup targeted three distinct markets: the Ultrastar 9ES addressed the entry-level SCSI market, the Ultrastar 9LP aimed at the enterprise-class server market, and the Ultrastar 9ZX wooed the top-performance 10k rpm market. This year however, an "Ultrastar 18LP" is conspicuously missing from the lineup. With only the screaming Ultrastar 18ZX to complement it, the 18ES seems to be left as Big Blue's entry in both the entry-level and enterprise-class markets.

The 18ES achieves its 18.2 gigabyte capacity using a full platter less than the Western Digital Enterprise WDE18300, weighing in at 3.6 gigs/platter. The drive's seek time is listed at a swift 7.0 milliseconds. Spindle-speed, of course, remains at a tried-and-true 7200rpm. A 2 megabyte buffer, seemingly standard for today's SCSI drives, rounds out the package. The drive is backed by an industry-standard 5-year warranty.

Unlike many other Ultrastar drives, the 18ES ships with write-caching enabled. Thus, the drive proved to be a quite straightforward installation into our Adaptec 2940U2W-equipped testbed. Let's take a look at some test results:

Wow, talk about some close results! All in all, the IBM Ultrastar 18ES performs quite similarly to the WD WDE18300. The IBM drive leads slightly in Windows 95 tests, with a Business Disk WinMark score about 4% higher than the WD. The 18ES' lead in the High-End WinMark, however, shrinks to an undetectable 1%. The match-up reverses itself under Windows NT 4.0. Here the IBM drive slips behind the WD unit by 3% on the Business Disk WinMark and 6% on the High-End tests.

ThreadMark 2.0 results were more one-sided. Here the Ultrastar 18ES lags behind the WDE18300 by 17% in Windows 95. The disparity increases under NT: the 18ES gets walloped by the WD drive, trailing it by 24%.

Following in the footsteps of its predecessor, the 18ES is quite unobtrusive. Idle noise was virtually undetectable. Seeks were quiet, along the same lines as the WD Enterprise. The drive also ran cool, though, subjectively, just a hair warmer than the WD unit. It's a disk that would easily work in a decently ventilated case without a drive cooler.

In summary, the IBM Ultrastar 18ES is a commendable successor to the popular Ultrastar 9ES. Since it stands as Big Blue's only low-profile 18 gigabyte offering, however, it has some big shoes to fill. The Ultrastar 9LP stood out as the leader of the pack when it came to enterprise-class SCSI disks, providing excellent performance with reasonable heat and noise levels. When compared to the competition's server-class drives, the 18ES is not a standout like the 9LP. The WD 18300, for example, provides comparable performance, actually edging by the 18ES in Windows NT, a more likely operating system when it comes to SCSI drives. Many would consider IBM to be a more "veteran" player when it comes to SCSI disks, something that may warrant consideration. Though our nod goes to the WD drive when comparing the two (due to marginally better NT scores along with its substantial lead in ThreadMark), one likely won't go wrong by choosing the Ultrastar 18ES instead.