Path: utzoo!attcan!uunet!tektronix!tekcrl!tekgvs!toma
From: toma@tekgvs.GVS.TEK.COM (Tom Almy)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Large number of files slows machine.
Message-ID: <4419@tekgvs.GVS.TEK.COM>
Date: 22 Dec 88 18:21:41 GMT
References: <8545@j.cc.purdue.edu> <7192@chinet.chi.il.us> <1078@pilchuck.Data-IO.COM> <10723@s.ms.uky.edu>
Reply-To: toma@tekgvs.GVS.TEK.COM (Tom Almy)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 25

In article <8545@j.cc.purdue.edu> tim@j.cc.purdue.edu (Timothy Lange) writes:
>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 the 512th file.

I have performed tests on my machine and found out that directory
searching performance drops off dramatically (*Orders of Magnitude*) when
there are more than 12*(number of block buffers specified in config.sys)
files in the directory.  Three suggestions (in order of value):

1). Move the files into multiple subdirectories.

2). Use a disk caching program -- this will typically improve all disk
    performance, but the performance drop off is still there, just not
    as dramatic.

3). Increase the number of block buffers with the config.sys buffers=
    command.  Beyond about 20, performance actually starts dropping, and
    you would need over 50!


Tom Almy
toma@tekgvs.TEK.COM
Standard Disclaimers Apply