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Western
Digital's 18Gig Ulta ATA66
Expert
WD-AC418000
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EIDE
Drive technology took another leap forward this year with the advent
of the Ultra ATA66 standard. Hot Hardware took a
close look at a 5400 RPM ATA66 drive a few months back.
This technology was fairly new then and it is still early on for the
ATA66 standard. However, with the recent addition of new
motherboards that are able to support this new higher bandwidth
standard and DMA66 drives, we felt it was time to look at another
from this field.
This is a run-down on a new drive from the perennial drive
manufacturer, Western Digital. Western Digital has been around
forever making high quality drives. Their reputation speaks for
itself. They have recently flushed out their ATA66 Drive line-up
with a bunch of 7200 RPM drives. These are drives that have a
spindle speed of 7200 RPM vrs. their slower siblings at 5400 RPM.
Here are the rest of the details...
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- Formatted
Capacity - 18,042 MB
- Interface
- 40-pin EIDE
- Actuator
Type - Rotary Voice Coil
- Number
of Platters - 4
- Data
Surfaces - 8
- Number
of Heads - 8
- Bytes
Per Sector - 512
- User
Sectors Per Drive - 35,239,680
- Servo
Type - Embedded
- Recording
Method - PRML
- ECC -
Reed Solomon
- Head
Park - Automatic
- Average
Seek (Read) - 9.0
ms typical, 9.5 ms maximum
- Average
Seek (Write) - 9.5 ms typical, 10.5 ms maximum
- Track
to Track Seek - 2.2 ms typical, 2.9 ms maximum
- Full
Stroke Seek (Read) - 15.5 ms typical, 18 ms maximum
- Full
Stroke Seek (Write) - 16 ms typical, 19 ms maximum
- Index
Pulse Period - 8.33 ms (nominal)
- Average
Latency - 4.17 ms (nominal)
- Rotational
Speed - 7200 RPM (nominal)
- Transfer
Rate (Buffer to Host) - 66.6 MB/s (Mode 4 Ultra ATA)
- 33.3
MB/s (Mode 2 Ultra ATA)
- 16.6
MB/s (Mode 4 PIO)
- 16.6
MB/s (Mode 2 multi-word DMA)
- Transfer
Rate (Buffer to Disk) - 139.61 Mbits/s minimum
224.31
Mbits/s maximum
- Interleave
- 1:1
- Buffer
Size - 2048 KB (2 MB)
- Error
Rate (Non-Recoverable) - <1 in 1013 bits read
- Spindle
Start Time From Power-on to Drive Ready - 18s typical, 31s
maximum
- Contact
Start/Stop Cycles (CSS) - 40,000 minimum
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There are a few
items on the above list that should make this drive shine. The 9 ms
(milliseconds) read and 9.5ms write is pretty snappy. Although we've
seen other 7200 RPM drives faster at around 7.5ms. However, this is
the first ATA66 capable 7200 RPM drive we have tested. It will be
interesting to see how it fairs vrs. the likes of our current
in-house favorite.
Another great feature for this drive is its HUGE Data Buffer/Cache
Size of 2MB! This should help to balance out the somewhat average
Average Seek Read and Write performance numbers.
OK, so enough
with the theories. Let's get the proof from the pudding...
WD
AC418000 Benchmarks here...
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