[Ti] Toshiba's New 100GB 2.5-inch HDD

[Kynan Shook]

Two notes:
First, it would certainly be *possible* to add another platter, but I 
doubt Toshiba would do it.  If you look at their 2.5" drives, all of 
them are 9.5 mm tall.  And, since it seems to me like Toshiba has been 
the one recently with the largest laptop drives, I'm not sure anybody 
else will beat them, either.  Additionally, all of Apple's current 
laptops are limited to 9.5 mm height drives; I'm going to bet that 12 
mm drives are quickly going the way of the 15 and 19 mm ones (or 
something like those sizes, might not be exactly right).


Also, as far as rotational speed versus size, you're missing one thing: 
there are 4 surfaces in both the 80 and 100 GB drives (both sides of 2 
platters), and the size of the platters are the same.  Hence the areal 
density is much higher (as they mention in the article) - likely about 
25% higher.  Now, certainly some of that added density will be added by 
putting more cylinders in the drive (eg increasing the radial linear 
density), but some of that added density is also added along the 
direction of motion; I'd say angular density, but that wouldn't be 
right (the angular density depends on the radius); so it's really just 
linear density along a particular arc that is being increased.  Anyway, 
  you're getting a drive that spins 23% slower, but bits are flying 
under the head almost as fast as a lower-density 5400 RPM drive.

The bottom line is this: if you really want speed, you shouldn't be 
using a laptop to begin with.  Go buy a G5.  If you want storage space, 
the 100 GB drive will probably be close to the same speed as the 5400 
RPM 80 GB drive (and faster than the 4200 RPM 80 GB drive).  If you 
don't want either, stick with what you've got.  If you want both, can I 
interest you in an Xserve RAID?


Sam Hotchkiss <ti at zlit.net> writes:
> On 4/22/04 4:57 PM, "John Griffin" <jwegriffin at mac.com> wrote:
>
>> Too bad it only rotates at 4200 rpm. When they can get it to spin at 
>> 5400,
>> it will be a real killer!
>
> My thinking is this... This is a 9mm drive... Which means 2 platters (I
> believe)...  The tibook can accommodate a 12mm drive (3 platters)... 
> So if
> these drives have 50gb per platter, that would mean a 150gb 12mm drive 
> would
> be very possible