STk I/O Performance

From: Andrew Joseph Kompanek <ak10+_at_andrew.cmu.edu>
Date: Wed, 12 Apr 1995 17:11:21 -0400 (EDT)

When I open a 34 K file and read characters, I get the following
performance (this is on an HP 9007s715):

(time (let ((ch (read-char port)))
    (while (not (eof-object? ch)) (set! ch (read-char port)))))

;; Time: 1520.00ms
;; GC time: 110.00ms
;; Cells: 68082


This is about 22K/second. A C program that uses fopen and getc on
the same machine gives about 2Mb/second.

Is a 100 time slow-down to be expected? Is there any way to speed
this up by changing buffering, etc?

It appears that my program is spending most of its time
in (peek-char ..) and (read-char ..)....

Thanks for any advice...
Drew
Received on Wed Apr 12 1995 - 23:13:09 CEST