PCBUILD Archives

Personal Computer Hardware discussion List

PCBUILD@LISTSERV.ICORS.ORG

Options: Use Forum View

Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Tom Turak <[log in to unmask]>
Reply To:
PCBUILD - Personal Computer Hardware discussion List <[log in to unmask]>
Date:
Tue, 30 Jun 1998 18:56:26 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (28 lines)
>>At 6/29/98 10:34 PM , Jim Meagher wrote:
>>
>>As I said in my previous post, the TOTAL amount of wasted space on a
>>particular PC is determined the number of files AND their size as compared
>>to the cluster size.
>
>
>Jim is exactly right. Several of the computers here at work show various
>savings for conversion to FAT32.
>
>Doug Simmons

Actually, if you forget about all the clusters that are full, the chances grow that the
median percentage of space wasted in a cluster exceeds 50% as the cluster
size increases.  In other words, more than half your files will be wasting 50% or more
of their last cluster.  Either way, the "1/2 times cluster size times total files" rule holds
pretty accurately if your disk usage tends to be dynamic, lots of file erasures and
creations, etc.

As for speed reading fewer FAT Table entries, your FAT should be cached.  Your
cache will be optimized if it has as many discreet clusters in it as it can.  If you fill it
with four clusters where there are room for 16, you may do more disk reads.  That aside,
caches have their own algorithms for dealing with this, so I won't hazard a guess as to
the real world consequences.  I would trust that smaller clusters give the best random
access and the best space usage.  If your system will delay writes, as mine does,
it would matter even less.  I don't think any of this has a real world impact on speed.
Tom Turak

ATOM RSS1 RSS2