Path: utzoo!mnetor!uunet!mcrware!jejones
From: jejones@mcrware.UUCP (James Jones)
Newsgroups: comp.sys.m6809
Subject: still more data re disk I/O
Message-ID: <593@mcrware.UUCP>
Date: 18 Jan 88 16:19:29 GMT
Organization: Microware Systems Corp., Des Moines, Ia.
Lines: 21
Keywords: floppy disk throughput

Well...I took my own advice and instrumented the program to announce
each step (creating/writing the file, reading the file, and finishing). 
(This is for that program that writes a 100K file and then reads it.)
Results are:

        version with SS_SSIZ       version without SS_SSIZ
write          2:43                         1:45
read           0:14                         0:14

(This is done with a CoCo 3, using a Sardis Tech floppy controller and
80-track 6ms floppy.)  14 seconds to read 100K comes to a tad over 7K
bytes/second.

So...it appears to take *far* longer to write a file than to read it.  The
SS_SSIZ cuts out a big hunk by avoiding repeated trips to the allocation
bitmap and the file descriptor sector, but I don't know where the rest of
the time is going.  It will be interesting to find out.

		James Jones

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