Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!purdue!i.cc.purdue.edu!j.cc.purdue.edu!tim
From: tim@j.cc.purdue.edu (Timothy Lange)
Newsgroups: comp.sys.ibm.pc
Subject: Large number of files slows machine.
Message-ID: <8545@j.cc.purdue.edu>
Date: 14 Dec 88 20:05:59 GMT
Reply-To: tim@j.cc.purdue.edu (Timothy Lange)
Organization: PC Learning Resource Center, Purdue University
Lines: 18

I am dealing with an user that has around 650 files in a subdirectory.
We noticed that accessing the files at the bottom of the DIR listing
is much slower than the files near the beginning.  The performance
really drops off at about 512th file.  Now I know that many files in a
directory is not good, so don't flame me.  I also know that a
directory entry take 32 bytes, a sector is 512 bytes, and on this
machine a cluster is 4 sectors.  He has 'BUFFERS=40' in his config.sys
file.  What is magical about 512 files?  I cannot figure out why that
number is significant (but it looks good!)  The first 500 or so files
are accessed quite rapidly, the rest have a terrible access time.  In
fact, for files of equal size, I can make a copy of the first ten
files ten times quicker than the last ten.  I would love some info
that explains my file access times.

Tim.

-- 
Timothy Lange / Purdue University Computing Center / Mathematical Sciences Bldg
West Lafayette, IN  47907 / 317-494-1787 / tim@j.cc.purdue.edu / CIS 75410,525