120GB - Page 1
8MB Buffer at
IDE Hard Disks!
on 7th of January 2002 announced the WD Caviar 120 GB Special Edition hard drive
that uses an 8 MB buffer - the largest buffer available today in a 7,200 RPM
desktop EIDE hard drive.
As Western Digital mentioned at the press release: "...The new WD Caviar
hard drive combines the speed and performance of the previously announced WD
Caviar 100 GB Special Edition 8 MB buffer with the massive capacity of 120 GB.
"This drive truly represents what can be achieved when speed and performance
are combined with capacity - the ability to handle users' most demanding applications
such as digital video editing and commercial applications such as entry-level
enterprise storage devices," said Rich Rutledge, vice president of marketing
for Western Digital. "These greater capacity drives open the door for new
types of usage that seemed far-fetched only a short time ago."
The WD Caviar 120 GB Special Edition 8 MB buffer hard drives provide a higher
percentage of cache hits and significantly faster time to data than industry-standard
2 MB versions. The larger 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. The 8 MB buffer can also offer
an advantage in a server environment, where data typically is accessed across
wider portions of the disks. With additional buffer resources, read and write
commands are more quickly queued and served to the user..."
With this review we examine how this "Special Edition" performs in
our test benchnech. Since we don't have any other 120GB model, we compare it
with the faster 40GB drives from Maxtor and WD.
For our tests, we received the retail box, which contained the WD120JB, a diskette
with various software, the ATA66/100 ribbon, mounting screws, a quick installation
guide and a printed manual in 3 languages. The drive is priced at around $379
at retail market:
drive has 7200rpm rotation speed, supports ATA100 interface connection and includes
an 8MB buffer. Looking at the drive's features, we see that Western Digital
is using 3 platters of 40GB each, 16.383 cylinders and 16 logical heads. You
can connect the 120GB drive through both PioMode4 and UDMA33/66/100 connection
interface. For our tests we installed the drive as a primary slave and worked
at ATA100 interface. Below are the main specifications of the WD1200JB:
Read Seek Time (Average)
Buffer To Disk
602.0 Mbits/s (Max)
Write Seek Time (Average)
10.9 ms (average)
Mode 4 Ultra ATA
Track-To-Track Seek Time
2.0 ms (average)
Mode 2 Ultra ATA
Full Stroke Seek
21.0 ms (average)
4.2 ms (nominal)
7,200 RPM (nominal)
Below are the screenshots from the drive's features as the DTemp software reports.
Note that the drive cannot report its internal temperature from SMART protocol
therefore no thermal tests will be done:
2. Seek Times Test
120GB - Page 2
Seek Times Test
As the test results show, Western Digital WD1200JB has an access time of 13.88ms
while reading and 12.88ms while writing. The drive produced outliers at both
reading/writing service times, 13/2343 respectively.
The Intel's IPEAK on-line help explains what outliers mean "...A well
behaved storage subsystems should have any outliers in the service time distribution
and the distribution should be narrow. Outliers in the distribution make the
storage subsystem unsuitable for real-time applications, such as multi-media,
where variations in service time are detrimental..."
3. WinBench 99 Tests
120GB - Page 3
WinBench 99 Test Results
At the Business WinMark99 test, the Western Digital WD1200JB performed very
well. The drive gave a 15250 score, which is almost double than the WD400BB
gave. At the High-End WinMark99 test, the drive also performs very well with
a score of 34450. Despite the drive's big capacity (120GB) it can score high
with the WinBench 99 software. As it seems, the increased buffer (8MB) gives
a higher performance...
Transfer Rate Tests
The WD1200JB drive starts reading at 46650Kb/s and ends at 28800Kb/s. The drive's
performance is very good and the "Data Density" graph does look quite
WD1200JB keeps its reading performance high until the first 20GB and then gradually
falls to 28MB/s at the end of the disc:
4. SCSI Mechanic Tests
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SCSI Mechanic Linear Reading/Writing Tests
We performed the SCSI Mechanic tests as described in our test methology guide.
The test results are illustrated in the following graph. Note that the measurement
unit is the Kb/s:
The performance for the WD1200JB in the "Sequential I/O" reading
test was around 38Mb/s, which is high enough for your A/V needs. The drive communicates
well with the IDE bus, and delivers 86690Kb/s at the "Same Sector I/O"
test. Lastly, in the "Random I/O" test, the performance is 12961Kb/s
higher than what Maxtor 6L40J2 gave.
In the linear writing tests, the WD1200JB drive performed also very well. In
the "Sequential" test, the drive gave 37848Kb/s. In the "Random"
test, it has 15693Kb/s and in the "Butterfly" test, 23858Kb/s. WD1200JB
is faster than any 40GB drive.
5. IPEAK/Heat Tests
120GB - Page 5
- Combined Read/Writing Tests
Intel's IPEAK test results combine both reading/writing actions and give a
weighted score based upon each drive's performance in each specific task. The
height of each bar is the measured mean service time per disk access for a drive
stimulated with I/Os from the given workload. Shorter bars represent better
performance. As we will see a drive that scores well in the "Desktop"
test doesn't mean that will perform the same in the "Server" mode
test, since the I/O operations are different.
In the above picture you can see the weighted (Average) score of all tested
drive. WD1200JB scored high enough to give a very low IPEAK Desktop weighted
score of 1.14. This is due to higher reads vs. writes at the "Desktop"
test. In the "Server" test, the drive delivers the lowest mark but
with lower performance difference than in the previous test. You can download
IPEAK test results over here.
- Heat Tests
The drive doesn't support such feature through the DTemp software.
120GB - Page 6
Western Digital WD1200JB is the first 120GB disk drive that arrived in our
labs. The drive has an 8MB buffer and according to Western Digital, will increase
the drive's performance especially when it is used at Servers, where lot of
read/write are occurred at the same time.
As our test results showed, the drive is very fast but it didn't perform better
than the 40GB disks at the IPEAK Server test. Intel's IPEAK "Server"
test contains lot of write and read operations on the disk. WD1200JB has high
seek times (13ms) for both reading/writing tasks. This could be an explanation
for the low performance of the drive in this test. SCSI drives are preferred
for servers; due to their very low seek times (under 5ms).
Most users who need such a high capacity disk will use it at normal modes,
and for this use the WD1200JB will be a good solution. The drive is very fast
and the 8MB of buffer does help and delivers the maximum performance at this
category. The price of the drive is around 379$, which is high enough but it
we believe it is worthy :-)