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Introduction:::...
I don't know if it's bad luck or changes
in technology but I seem to have been bogged down
lately with reviews that seem to be taking for ever
to complete. The more you try to obtain accurate and
repeatable results the more you realise that that's
a far more difficult task than it sounds of late,
and I'm not just talking about graphics cards either.
When this hard drive first arrived on
my doorstep some time back I assumed that testing
it was going to be a simple affair. I was wrong. With
results from the same batch of benchmarks varying
by as much as 300% it was looking like time to investigate
a new method of testing.
Look around the 'Net and you'll see
there's no shortage of hard drive benchmarks, unfortunately
many of them offer measurements of parameters that
are of only limited usefulness to somebody who really
has no desire to spend six months studying the innermost
technicalities of hard drive geekery. No, what I wanted
was a few relatively simple tests that would give
results that we can all understand.
That proved to be only half of the battle
though. Just as every benchmark gave differing results
for supposedly the same tests, so it seemed that different
platforms introduced varying errors to the final figures.
AMD users will no doubt feel aggrieved when I tell
you that by far the tightest sets of figures were
achieved throughout on Intel platform motherboards
and as a result of this I've decided to standardise
all future hard drive benchmarks by running them on
a specific i865 based test system.
Anyway, that's a little of the background
to this review out of the way, time to talk a little
bit about our subject. The WD2500JD is a capacious
250GB comprising three 83GB platters spinning at 7200RPM.
The "JD" suffix proclaims
this as an 8MB cache model with Serial-ATA interface
("JB" denotes the Parallel-ATA version)
and conventional ball type spindle bearings.
Sit tight and we'll do the specs!
WD CAVIAR SE PRODUCT
BENEFITS
- 8 MB cache buffer – fast data transfer from a
cache four times larger than the industry-standard
2 MB size.
- 7200 RPM – high-performance rotational speed for
high-capacity hard drives.
- Data Lifeguard Tools™ – software utility that
works in conjunction with the embedded Data Lifeguard
features (including shock protection, an environmental
protection system, and embedded error detection
and repair features) to make hard drive management
diagnostics and repair simple and worry-free.
- SecureConnect™ – provides a 500 percent stronger
cable-to-drive connection than first-generation
SATA hard drives and cables; ensures backward compatibility
with legacy SATA cables and backplanes.
- FlexPower™ – connector technology that accepts
power from both industry-standard and new SATA power
supplies.
- Point-to-point bus configuration – utilizes the
full bandwidth of each drive interface in a networked
environment.
- Hot plug support – ability to swap out a hard
drive without having to power down the system or
reboot promotes system design flexibility, data
availability, and serviceability.
- Backplane compatibility – promotes expandability
and flexibility in system architecture.
- Longer, narrower cable – prevents incorrect mating
and bent pins, providing greater reliability and
reduced service calls.
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| Physical Specifications |
| Formatted Capacity 1 |
250,059 MB |
| Interface |
1.5 Gb/s Interface
(Serial ATA 1.0) |
| Bytes Per Sector (STD) |
512 |
| User Sectors Per Drive |
488,397,168 |
| Dedicated Landing Zone |
Yes |
| Actuator Latch/Auto Park |
Yes |
|
| Performance Specifications |
Data Transfer Rate
- Buffer to Host
- Buffer to Disk |
150 MB/s 2
748 Mbits/s max |
| Average Read Seek |
8.9 ms (average) |
| Track-to-Track Seek 3 |
2.0 ms (average) |
| Full Stroke Read Seek 3 |
21 ms (average) |
| Average Latency |
4.2 ms |
| Rotational Speed |
7200 RPM |
| Read Cache |
Adaptive |
| Write Cache |
Yes |
| Buffer |
8 MB |
| Drive Ready Time |
9.0 sec (average) |
| Start/Stop Cycles |
50,000 minimum |
| LBA Support |
Yes |
Error Rate
(non-recoverable) |
<1 in 1014 bits read |
|
| Physical Dimensions |
| Height |
English: |
1.028 inches max |
| |
Metric: |
25.4 mm max |
| Length |
English: |
5.787 inches max |
| |
Metric: |
147.0 mm max |
| Width |
English: |
4.00 inches ±0.010 inch |
| |
Metric: |
101.6 mm ±0.25 mm |
| Weight |
English: |
1.32 pounds ±0.13 pounds |
| |
Metric: |
0.60 kg ±0.06 kg |
|
| Power Requirements (average) |
| Mode |
RMS Current
|
Power |
| |
12V (±10%) |
5V (±5%) |
|
| Read/Write 4 |
530 mA |
850 mA |
10.6 W |
| Idle |
510 mA |
780 mA |
10.0 W |
| Standby |
30 mA |
300 mA |
1.8 W |
| Sleep |
30 mA |
190 mA |
1.3 W |
|
| Environmental Specifications
5 |
| Shock |
| Operating
(2 ms) |
30G (write), 65G (read) |
| Non-operating (2 ms)6 |
250G |
| Vibration |
Operating
- Random
- Linear |
0.004 g2/Hz (10 to 300
Hz)
20-300 Hz, 0.75G (0 to peak) |
| Non-operating - Linear |
5-20 Hz, 0.195 inches (dbl amp)
20-500 Hz, 4.0G (0 to peak) |
| Operating Temperature
and Humidity |
| Temperature |
5°C to 55°C |
| Humidity |
5-95% RH non-condensing |
| Thermal Gradient |
20°C/hour (max) |
| Non-Operating Temperature
and Humidity |
| Temperature |
-40°C to 65°C |
| Humidity |
5-95% RH non-condensing |
| Thermal Gradient |
30°C/hour |
| Acoustics (average) |
| Idle Mode 7 |
34 dBA |
| Seek Mode 0 7 |
36 dBA |
| Seek Mode 3 7 |
35 dBA |
| Reliability Specifications |
| Warranty |
3 years 8 |
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1
Western Digital defines a megabyte (MB) as 1,000,000
bytes, and a gigabyte (GB) as 1,000,000,000
bytes.
2 Effective maximum transfer rate
running Serial 1.0.
3 On reads and writes.
4 20% duty cycle.
5 No non-recoverable errors during
operating tests or after non-operating tests.
6 Half sine wave measured in 2 ms
duration, measured without isolation.
7 Sound power level.
8 Three-year standard warranty on
WD Caviar Special Edition hard drives. This
standard warranty may be subject to variations
imposed by local law or regulations.
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