>If the performance of the outer tracks is better than the performance of the
>inner tracks due to limitations of magnetic density or rotation speed (not
>being limited by the head speed or bus speed), then the sequential
>performance of the drive should increase as a square function, going toward
>the outer tracks.  c = pi * r^2

Decrease because the outer tracks are the lower numbered tracks; they
have the same density but they are larger.

>So, small variations of sequential performance are possible, jumping from
>track to track, but based on what I've seen, the maximum performance
>difference from the absolute slowest track to the absolute fastest track
>(which may or may not have any relation to inner vs outer) ... maximum
>variation on-par with 10% performance difference.  Not a square function.

I've noticed a change of 50% in speed or more between the lower and the
higher numbers.  (60MB to 30MB)

In benchmark land, they do short-stroke disks for better performance;
I believe the Pillar boxes do similar tricks under the covers (if you want 
more performance, it gives you the faster tracks)


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