Re: Hard Disk sizes (was: New Member needs mass storage)

[bnm@ornl.gov (Brooks N. McNeely)]

At 01:15 PM 5/17/96 EST, Peter W. Borders wrote:
>Since when is the definition K = 2^10 (1024) non-standard IN RELATION 
>TO COMPUTERS? Do you measure your computer's memory in powers of 10? 
>All the harddisk manufacturers are doing is confusing the general 
>public by using one value for K for harddisks and another for 
>anything else to do with a computer. My .02 worth.
>
Memory is addressed using binary addresses, so if memory wasn't based on a
power of 2, we would have memory that couldn't be addressed (for all intents
and purposes not there), or addresses without memory (probably lots of
problems here).

OTOH, hard disk geometries allow lots of different combinations, _most_ of
which are not a power of 2. So 16Mb of memory is an exact number when 1Mb =
1024 x 1024, while a 540Mb hard drive will be an approximation regardless of
whether 1Mb = 1000 x 1000 or the other definition.

Since there is no compelling reason to choose either standard for hard
drives, while there is for memory, the manufacturers choose the method which
makes their products look the best as far as hard drives are concerned.

My memory (which has been failing me lately) was that IBM used to use the
same method, or at least a much more conservative one, when they advertised
memory and hard drive sizes. When they saw what that their competitors were
doing, they changed their advertising also. When they got beat up over the
change, they started including a standard paragraph in their long-winded
announcement letters specifying how size calculations were made.

$.02 more for the pot.

Brooks