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LispM's crummy I/O performance (was RE: LispM Market Share)
Date: Tue, 16 Jan 90 16:32:58 -0500
Lets get quantitative about this.
? Why is LISPM I/O is slow?
? What is a good way to measure relative performance given hardware
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.