Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!deimos.cis.ksu.edu!calvin.ksu.ksu.edu!neil
From: neil@calvin.ksu.ksu.edu (Neil Erdwien)
Newsgroups: comp.lang.postscript
Subject: Re: Postscript Printer Speed less than ratings
Keywords: Speed memory programming time timing
Message-ID: <5289@deimos.cis.ksu.edu>
Date: 10 Dec 89 21:09:34 GMT
References: <372@timer1.UUCP>
Sender: nntpd@deimos.cis.ksu.edu
Reply-To: neil@calvin (Neil Erdwien)
Organization: Kansas State University Computing and Telecommunications
Lines: 62

In article <372@timer1.UUCP> fritz@timer1.UUCP (fritz) writes:
>I have a NEC LC-890 with 1 Meg memory running in Postscript Batch mode. 
>at 19200 on a serial line.
>
>It takes approximately 60 seconds to print a 45K chart in this format
>
>.
>.
>.
>/L {lineto} def
>/LS {lineto stroke} def
>/M {moveto} def
>.
>.
>.
>
># # M # # L
># # L
># # L
># # L
>.
>.
>.
># # LS %stroke every 100 L's to keep stack small
># # M # # L
># # L
># # L
># # L
>.
>.
>.
>showpage

Adobe has a document that describes some printer driver speedups.  It is available
from their file server.  For more info, send mail consisting of only the word 'help'	to ps-file-server@adobe.com.

Warning:  That address is an MX address.  If your mailer can't handle MX addresses,	use this address: ps-file-server%adobe.com@decwrl.dec.com.

The file you want is 'case_study.ps' from the Documents directory.

In the above code, I'd suggest you change the definitions to:

/L /lineto load def
/LS {lineto stroke} bind def
/M /moveto load def

The basic idea in these changes is to save the interpreter some work.  The way
you have the procedures defined, when they are interpreted and call the real
lineto, moveto, and stroke, they are called "by name" for lack of a better term.
In other words, the name "lineto" has to be looked up to find the corresponding
definition.  By doing a 'load', the name is turned into the executable object
when the procedure is defined.  I presume the executable object is an actual
pointer to a ROM subroutine.

I'd be very interested to hear how much this speeds up the printer.  When I did
some similar changes, I got a reasonable speedup, but not massive.  10%-20% is
what I remember.

--
Neil Erdwien
Kansas State University
neil@ksuvm.ksu.edu  or  neil@calvin.ksu.ksu.edu