LispM's crummy I/O performance (was RE: LispM Market Share)

["William D. Gooch" <ai.gooch@MCC.COM>]

    Date: Tue, 16 Jan 90 16:32:58 -0500
    From: magerman@linc.cis.upenn.edu
       
	 Lets get quantitative about this.
	 ?  Why is LISPM I/O is slow?
	 ?  What is a good way to measure relative performance given hardware
	    differences? 

    Now, anyone who has touched UNIX knows that reading in a 5meg file and
    even allocating memory for 1 million tokens (which are represented as
    integers) takes on the order of a few minutes (at most).  The LispM
    took almost over 5 hours to read in the data set!  This is on a 3650
    under 7.2.  What's more, the same LispM took almost 48 hours to dump
    the data (via NFS to a disk on a SUN4)!

There isn't enough data here from which to draw any firm conclusions.
The slowness you are seeing could be due to any number of things other
than just LispM i/o.  Have you done any metering to find out where the
time is really being spent?

A simple measurement I did a couple of years ago indicated that
character i/o on a 3640 or 3650 was about 10x slower than in C on some
type of Sun, I think a Sun4.  I hesitated to mention this because I
recall too little about the test to provide a complete report, but
suffice it to say that I was very discouraged by what I found.  More
recently, I ran a similar test on an XL400 and was pleased to see that
line-oriented reading is about 2x faster than on a 3640 or 3650, and
that character-oriented reading (where the 10x difference above was
seen) is around 5x faster.