Strange disk i/o behaviour

[Jörg Begemann]

Hello,

playing with pack and unpack I discoverd a strange and 
reproducable behaviour.

The following little code


#!/usr/bin/perl

$zerobuffer = chr(0) x 8192;

print "zerobuffer: ", length($zerobuffer), "\n";

$test = "test.dat";

open (OUTPUT, ">$test" ) || die "Fehler open";
binmode OUTPUT;

for ($rec=1; $rec<=500; $rec++) {
    print OUTPUT "$zerobuffer";
    print "REC #$rec geschrieben\n" if ( ! ($rec % 100) );
}

close (OUTPUT);



needed about 15 seconds on my AlphaServer_800 with 
OpenVMS V8.3 and perl v5.8.6 .

Changing the $zerobuffer to other characters than zero, 
the running time of this program on my machine lasted only 
3 seconds.

Is there a work around to speed up the program when writing 
character zero to disk?

Thank you in advance,

   Joerg Begemann