[Ti] 60gb TravelStar - quick question

[Sherman Gregory]

At 3:06 AM +0900 1/15/03, XXL wrote:
> >
>> On Tuesday, January 14, 2003, at 12:32  PM, Sam Hotchkiss wrote:
>>
>>> he 4800 rpm drives are actually faster than the 5400 rpm drives
>>
>> Please elaborate.
>
>Much higher track density so the actual throughput is higher even at the
>slower rotational speed.  IBM is shipping 7200 RPM Travelstars. "real soon
>now" and those will probably be extremely good for DV capture.
>-Joel
>

I would agree with this if you were comparing a 40GB at 5400RPM to a 60GB drive at 4800.  In that case the 60GB/4800RPM drive would be

     
       60 * 4800
    ---------------  = 1.33333   Times as fast as the 40GB/5400RPM Drive.
       40 * 5400


I am assuming that the media area on each of these is the same, and that the larger drive has a higher bit density.

If I am comparing two 60GB drives with the same media area (same size, same number of surfaces) then I would still think that the higher RPM drive would be faster.

So, by my thinking, the real speed factor is (capacity)/(media area) * RPM.  Probably more correctly (capacity)/(media length) * RPM, where the media length is the total length of all of the tracks.

Seek time is of course critically important to the real usable speed also.

      Sherman