One of the major issues facing a prospective hard drive purchaser is
the decision between an ATA or SCSI hard drive. It often seems that
ATA offers the tantalizing benefit of many gigabytes for cheap while
SCSI promises better performance at a higher cost. SCSI drives do not
benefit from the economies of scale that ATA drives enjoy; as the "performance"
rather than "mainstream" offering, SCSI drives outright cost
more to manufacture in addition to sporting beefier margins for distributors
and vendors. The addition of a SCSI controller to a system, whether
an add-on card or built in to the motherboard, can not be ignored. Finally,
SCSI drives tend to incorporate later technologies and better specs:
higher rotation speeds, larger buffers, faster seek times, etc. All
this translates into lots of expense.
Once in a while a manufacturer will produce the same mechanical drive
in both an ATA and SCSI configuration. Quantum has done so with its
Fireball series, the latest "SE" iteration being available
in Ultra ATA and Ultra SCSI models. We decided to pick up 6.4 gigabyte
versions of both and compare them head-to-head. The Ultra ATA protocol
boasts a maximum transfer rate of 33.3 MB/sec compared to Ultra SCSI's
20 MB/sec. In the tests we performed, the testbed's boot drive (Seagate
ST34555W) was inactive while the SCSI Fireball SE ran the tests. In
the ATA Fireball's case, only one ATA device can be active at any given
time per ATA channel. Either way, the maximum transfer rates were moot
neither drive comes close to saturating their respective interfaces.
The Quantum Fireball QM36400SE has a rotational speed of 5400 RPM,
the maximum currently found in shipping ATA drives. Its buffer is on
the low side, a relatively skimpy 128k. Quantum rates the Fireball SE's
average seek time at 9.5ms. The drives use 2.1 GB platters.
All this combined to give the ATA version a very respectable showing
in our 6.4 GB ATA roundup.
For this test, we used an Abit LX6 motherboard (v1.1, bios v C7Q),
a 266 MHz Intel Pentium II processor, a 64MB 10ns SDRAM DIMM, and a
Matrox Millennium II PCI 4MB (bios v1.2, Powerdesk v3.80). The tests
were run at 1024x768 with 24 bit color at 85 Hz using small fonts. ZDBop's
Startup Manager was used to prevent loading of background applications.
ZDBop's WinBench 98 v1.0's Disk Test Suites were run on the two drives.
The SCSI controller used with the QM36400SE-S was the Adaptec AHA-2940U2W.
Read caching and write caching were enabled. The boot drive (Seagate
Hawk 4XL ST34555W) contained Windows 95 OSR 2.1 patched with Intel's
82371xB INF Update. For the QM36400SE-A, Windows 95 OSR 2.1 was installed,
patched with Intel's 82371xB INF Update and Microsoft's REMIDEUP.EXE
fix. The boot drive (Western Digital Caviar AC31600) resided on the
primary ATA controller with the QM36400SE-A on the secondary channel.
Here is a link to the test bed