[mythtv-users] OT: best way to connect IDE harddrives and dvd
chris at cpr.homelinux.net
chris at cpr.homelinux.net
Mon Sep 18 18:47:11 UTC 2006
On Mon, Sep 18, 2006 at 01:45:12PM -0400, Matt Mossholder wrote:
> My understanding is that it would go something like this:
> sector 1 / platter 1 = LBA 1
> sector 1 / platter 2 = LBA 2
> sector 2 / platter 1 = LBA 3
> sector 2 / platter 2 = LBA 4
> ... and on down the line. Vertical movement first, then around the edge,
> then towards the center.
It's around the edge first. It takes a finite but significant
amount of time for the drive to change from one head to another.
(http://www.pcguide.com/ref/hdd/perf/perf/spec/trans_HeadSwitch.htm)
If you changed heads after every sector then you would have a
small delay between each sector, and when it's time to move back to
the first platter you would have a rather large delay waiting for
the next sector unless the drive also had sector interleave (ie: a
4-head drive would need a 5:1 sector interleave in order to have
sector 2 available for head 0 after sector 1 was read by head 3.)
This would kill the "sustained transfer rate" of the drive. The
fastest way to get data off the drive is to read an entire track
into the buffer at once.
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