Lyvim Xaphir wrote:
> A drive's sectors actually start out on the rim of the drive. In that
> area, you have more sectors per track (outer rim) than as you go closer
> towards the spindle. At the spindle you have the lowest sectors per
> track. Both the data rate and the sectors per track are greatest at the
> rim of the hard drive; which is where the boot sector is too btw. The
> heads can stay on one track and transfer more contiguous data per
> cylinder on cylinders at the rim than they can close to the spindle.
This is true, but you also need to take into account how long it takes
for the heads to get to the right bit of the disk.
When a hard drive is asked to read (or write) data, it has to move the
read heads to the right track. Then it has to wait for the right bit of
data to come around.
For short reads and writes (a few hundred K or less), the time for the
head to get into the right place is going to be a lot more than the time
for the head to actually read the data.
So for small accesses, you do better by locating the data in the middle
of the drive somewhere, so the head hasn't got quite so far to travel
and can get there faster.
It's not unknown for administrators to limit the amount of data that
they will store on a disk so the heads don't have to travel too far...
James.
--
E-mail address: james | Practically any car advert, for example, shows you
@westexe.demon.co.uk | that if you buy this car you will get so lost that you
| end up parked (well, no. The word here is "stuck") on
| a mountain in Monument Valley. -- Telsa Gwynne
