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December 6th, 2010, 1:39
After examining the Western Digital VelociRaptor drives
Except for "Capacity" and "User Sectors Per Drive", both the Western Digital VelociRaptor 450 GB (WD4500HLHX) and Western Digital VelociRaptor 600 GB (WD6000HLHX) hard disk manufacturer specifications are identical,
including the weight specification.
At this time, I do not have a Western Digital WD4500HLHX drive to examine.
Are the WD4500HLHX model drives WD6000HLHX drives using different firmware?
December 7th, 2010, 4:15
Most probably they have different firmware, and the 600gb version uses one more head than the 450gb.
December 7th, 2010, 19:42
WD's spec sheet states that the two drives have identical maximum sustained data transfer rates, 145MB/s. This would confirm that they are using identical platters, and that the difference is in the number of heads.
http://www.wdc.com/wdproducts/library/S ... 701284.pdf
January 30th, 2011, 0:27
450GB has 5 heads
600GB has 6 heads
January 30th, 2011, 1:00
Doomer wrote:450GB has 5 heads
600GB has 6 heads
That works out to 90GB per head for the 450GB drive, and 100GB per head for the 600GB.
Are you sure that's correct?
Instead, 4 heads versus 3 heads would give identical figures of 150GB per head for each drive.
January 30th, 2011, 1:59
fzabkar wrote:Are you sure that's correct?
positive
January 30th, 2011, 6:38
AFAICS, that would mean that the 450GB drive is short stroked, which would suggest that it should have better average seek times.
I notice that the 300GB, 150GB, and 74GB models have identical maximum sustained data transfer rates of 126 MB/s. This would suggest that they have identical data densities of 75GB per head. So the number of heads would be 4, 2, and 1, respectively.
The 600GB and 450GB have a transfer rate of 145 MB/s. This would imply that their data density is ...
(145 / 126)^2 x 75 = 99.3 MB per head
This confirms that they have 6 and 5 heads, respectively.
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