memory management pentaho

good morning

I noticed that the process java / tomcat never exceeds 1.7 GB of 6 GB allocated to the operating system.

I want to assign more memory to pentacho to speed up the loading of pages.

opt/pentaho/biserver-ce/start-pentaho.sh the variable "export CATALINA_OPTS" is set in this way:

export CATALINA_OPTS="-Xms256m -Xmx768m -XX:MaxPermSize=256m -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000"


How do I change the parameters to increase the memeria usable?

thanks