have a several PCs running WinXP SP2 and W2k SP2 latest patches.  all have AMD
or Intel chips with at least 1 gig ram.

have Java applet that at times requires ~250 meg of ram.  on some boxes it
runs in less than 1 min on other takes over 30 mins.  

on ones with 30 mins i notice mem never goes over 150 meg ram usage in task
manager even when box has 600 meg free.  on boxes with 1 min time it goes to
250 megs and finishes.

i have tried all versions of Sun JVM from 1.4.2 to 1.6

i went to http://www.duckware.com/support/javahelp.html and noticed that on
boxes that are fast in the Java VM: Your Java VM reports the following
diagnostic information: section in max mem it said >128 meg or >256 etc

on slow boxes its says  max memory: 93 meg.

there are no settings in the java plugin

can anybody please explain