Nearly five months ago, early birds such as Quantum and Seagate announced next-generation 20 GB/platter 7200 RPM ATA drives that made the mouths of hardware enthusiasts water. A bit later, Western Digital announced its unit... with a twist: they actually started shipping the drive within a couple weeks. As a result, WD's Caviar 400BB was the first next-generation unit on the market. Though it's been available for a couple months now, the 400BB hasn't generated nearly as much buzz with StorageReview.com readers as Quantum's Fireball Plus AS has.
So what's the big deal about the AS? The answer starts with Quantum's original 7200 RPM unit, the Fireball Plus KA. Many observers noted that the KA's specs bore more than a passing resemblance to the company's Atlas IV SCSI drive. The only real difference appeared in seek times... and even here the KA overachieved, further narrowing the difference between the two drives. It was apparent that Quantum's drives featured a single design that was adapted to both interfaces. While it didn't have a direct analogue, the Fireball Plus KX's superior access times made it obvious that it too featured an actuator suitable for SCSI drives. And finally, the Fireball Plus LM featured specs similar to the Atlas V. And, yes, an exceptional access time as well.
Why the fixation on access time? All the hoopla about interfaces aside, it's physically faster accesses that set SCSI drives ahead of their ATA counterparts. Swift access times deliver great benefits in most applications. Remember also that access time is (mostly) the sum of seek time and rotational latency. The latter, the average time it takes for the correct sectors to rotate under the drive's heads, is fixed at 4.2 milliseconds for 7200 RPM drives. We measured the Fireball Plus LM's access time at 11.5 milliseconds. As a result, despite its specified seek time of 8.5 milliseconds, the LM's measured seek time weighs in at just 7.3 milliseconds. How often do we witness a product beating its specs by more than 15%?
Quantum has stated that the Fireball Plus AS is the first unit designed from the ground up for the ATA interface. Why? The implication is that such design allows engineers to tweak performance to the interface. It's likely, however, that there were also some economic and pragmatic reasons why the Fireball Plus and Atlas lines shared parts. With the demise of the 7200 RPM Atlas (there will be no Atlas VI), though, there's no longer a need to keep the actuator competitive with SCSI units. Does this spell the end of overachieving seeks? We're about to find out .
The Fireball Plus AS is Quantum's latest entry into the 7200 RPM ATA market. It features a contemporary 20.4 GB/platter density combined with up to three platters, yielding a flagship capacity of 60 gigs. Like all its predecessors, the AS' seek time is specified at 8.5 milliseconds. The drive features a performance-standard 2 meg buffer. A three-year warranty rounds out the package.
This Fireball is the first to debut Quantum's "Hydrodynamic Bearing motors" (HDB motors) as an option. HDB is not unlike the fluid bearings found in products from Seagate and Fujitsu where a viscous liquid is substituted for conventional ball bearings, lowering the noise floor while increasing reliability. The model reviewed here features standard ball bearings. A review of an HDB unit will follow in the future.
The AS is one of the first of a new breed of drives that ships exclusively with the ATA-100 interface. Remember that since ATA drives have yet to break sequential transfer rates greater than even 40 MB/sec that ATA-66 (and in most cases, even ATA-33) interfaces will run the drive with optimal performance. Our testbed remains equipped with a Promise Ultra66 controller.
So, without further ado, let's move on to the page that all eyes will be scanning: low-level results.
WB99/Win2k Low-Level Measurements