On Thu, 4 Jan 2001, Richard Rauch wrote:
> I'm also still not sure how many ``some'' amounts to.  Is it commonplace,
> or rare?  Something that only expensive drives do?  (Most drives still
> have RPM numbers associated with them; if they achieve the differing
> densities by rotating at different speeds, then a single RPM is at best
> misleading.)

I'd say all modern drives have varying numbers of sectors per track... and
it's not that the data density really varies; the outside tracks have more
area, and hence can fit more sectors.