Today we have a look at the latest and hopefully greatest ATA hard disk drives from IBM and Western Digital and compare them with the Maxtor D740X. In our recent ATA 133 review the D740X came out very strong, besting our ATA 100 reference disk in all categories. In autumn 2001, when Maxtor launched the D740X series, it was safe to say that it was together with IBM's 60GXP the fastest ATA disk around. The question is: Can the D740X hold on or do the newcomers dethrone it?

The Hard Disk Drives in this Test:
| Manufacturer | Western Digital | IBM | Maxtor | |
| Series | Caviar |
Deskstar
|
DiamondMax Plus D740X | |
| Model Number | WD400BB | WD1000JB | IC35L040AVVN07 | 6L020J1 |
| Storage Capacity | 40 GB | 100GB | 40 GB | 20 GB |
| Disk cache | 2MB | 8MB | 2MB | 2MB |
| Spindle speed | 7,200 rpm | 7,200 rpm | 7,200 rpm | 7,200 rpm |
| Platters | 2 | 3 | 1 | 1 |
| Heads | 4 | 6 | 2 | 2 |
| Interface mode | ATA 100 | ATA 100 | ATA 100 | ATA 133 |
| Warranty | 3 years | 3 years | 3 years | 3 years |
| Expected lifespan | 5 years | 5 years | 5 years | 5 years |
We would have preferred to compare disks with the same capacity. That however was not possible as the tested Western Digital "JB" series is not available in the mainstream 40 GB storage capacity which we use as reference to compare our results. On the other hand, the Maxtor D740X is not available in a 100 GB version.
Maxtor
DiamondMax Plus D740X
The D740X's prominent feature is its ATA 133 capability. In theory
ATA 133 is providing 33% better bandwidth than ATA 100. The general
understanding however is that ATA 133 gives headroom which is
not useable. High-end ATA 100 hard disk drives transfer around
40~45 MB/sec. They are running at "only" 40% to 45%
of their theoretical maximum transfer speed, because cables, connectors,
and magnetic interference as well as the OS layer, firmware, and
drivers are limiting factors. The good D740X performance seen
in our previous review is probably the result of improvements
in some of the many others areas that determine hard disk performance
such as the mechanics, the control circuitry including the disk
microprocessor, and the firmware. But it is most probably not
related to ATA 133. Whatever the reason is, the D740X performed
clearly better than our reference ATA 100 disk. The D740X is available
with a "fluid" or "ball" bearing motor and
comes in 20, 40, 60, and 80 GB. We used the 20 GB version for
our test. The Maxtor D740X product data sheet with more details
can be found here.

Western
Digital Caviar 1000JB
The "JB" hard disk drives come with an 8 MB disk cache/buffer
and has therefore a unique position in the ATA disk market: Regular
ATA disks, such as the other contenders in this test, have only
a 2 MB cache. In theory the larger cache (or buffer) improves performance because there is a reduction in the number
of physical accesses to the disk. This allows data to stream from
the disk uninterrupted by mechanical operations. Obviously Western
Digital intended initially to offer an 8 MB cache only for their
high-end disk with 100 GB for a limited period of time and called
it therefore "Special Edition". Due to high market demand
for the initially launched 100GB capacity version a complete "Special
Edition" line-up has been established and comprises now 80
GB, 100 GB and 120 GB versions. We tested the 100 GB model with
the product number "1000JB". The product data sheet
can be found here:

IBM
Deskstar 120GXP
The 120GXP is the latest descendent of a very successful line
of hard disks, which consistently made it to the top in competitive
tests. Unfortunately the GXP line included also a "bad child",
the 1999 released 75GXP. Although performing very well and initially
the top choice for high-end users, the 75GXP was later troubled
by an obviously unusual high failure rate. Our 75GXP "autopsy"
is here. It looks like that IBM could later solve
the obviously heat related problem with the even faster successor
to the 75GXP, the 60GXP. Unfortunately there are some reports
of similar failures in that series also. At first glance IBM's
120GXP looks quite unspectacular as it offers neither ATA 133
nor a bigger than usual disk cache/buffer. Like the Maxtor D740X
the IBM 120GXP 40 GB version comes with only 1 platter. Fewer
platters are mechanically desirable because it reduces noise and
vibrations; the mass the spindle has to move is smaller, and problems
aligning the heads are less likely. The 120GXP, available since
the beginning of 2002, comes in 20, 40, 60, 80,100 and 120 GB
versions. We tested the 40 GB version. A very detailed 120GXP
product data sheet can be found here (warning: 197 pages!)
