Linear velocity is only relevant to CDs, DVDs, etc. AFAIK, hard drives
still use constant angular velocity and data content is the same on all
tracks/cylinders. While it would be smart to put frequently accessed
data on adjacent cylinders, apart from some OS files (which may already
be optimally positioned), a static defragger app has no way of knowing
disc access patterns and thus no way of knowing what is optimal.
In the older world of FAT16 and FAT32 the directory is stored on the
outer tracks. Since the directory is frequently accessed it probably
makes some sense to locate frequently accessed (small) files toward the
outside (assuming you know what they are). However, more modern file
systems locate the directory structure toward the center in order to
minimize total head movement during directory searches.
I would still maintain that defragger vendors perhaps used to have a
valid PC marketplace that ended with OS/2 (HPFS) and Win NT (NTFS). But
today I suspect most are selling snake oil.
Chuck Norcutt
On 8/14/2012 1:14 PM, usher99@xxxxxxx wrote:
> Dr. Disk writes:
>> If defragmentation made a
>> significant performance difference I would say that your file system
> is
>> probably FAT32 (vs NTFS) and your disk must have been near full at
> some
>> point. If that's not correct I'd like to know.
>
>
>
> Hmm, I am not a computer engineer but isn't the data transfer rate
> higher on the outside part of the platter?
> The angular velocity is the same of course but the linear velocity is
> much higher towards the outside.
> Having the head find the most used files and applications there w/o
> moving around would suggest
> better performance in at least two ways. I think in the past people
> would create a partition on the outside and not used the inner one much
> at all---"short-stroking" I think it was/is called. So this is less
> relevant now?
>
>
> Fragmented understanding of this now, Mike
>
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