There is a good documentation about this at: http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html
Its for Java 6 but I think it's appliable for Java 1.5 also. I made some test running 1.6_u1 with the: -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode and it's a lot slower but the gc is more stable. Also when I tried the -XX:MaxGCPauseMillis=500 the result was muchs slower so I rather live with the pause than running so slow. Mor info about ergonomics at: http://java.sun.com/j2se/1.5.0/docs/guide/vm/gc-ergonomics.html We did upgrade to java 1.6u1 which was a very good performance booster, try that. /Per Jonsson -----Original Message----- From: Darren Kukulka [mailto:[EMAIL PROTECTED] Sent: den 20 april 2007 11:52 To: Tomcat Users List Subject: Ideal JVM params for 64-bit? Hi Tomcaters! Just a quick query relating to Tomcat 5.5.20 on Win2K3 with SUN JVM 1.5.0_10 (64-bit).... What are the ideal JVM GC parameter settings for a system with two dual-core processors and 4GB RAM (of which we've allocated a little over 3GB to the JVM)? Sometimes Tomcat pauses for a long time when OldGen gets close to full to perform a full GC... my JConsole session tends to drop out, although I can re-establish a session less than a minute later...users logged into the application experience no response which then returns to normal once the GC is finished. Cheers, Darren K Connaught wins RoSPA Gold Award for fourth year running Considerate Contractor Gold Award in 2006 Partnering Contractor of the Year Award in 2005 Please visit our website to see a full list of Connaught?s Registered Companies www.connaught.plc.uk/Investors/Registered-Companies Disclaimer: The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete this message. Connaught plc, Head Office 01392 444546 ******************************************************************************** This e-mail and the information it contains may be privileged and/or confidential. It is for the intended addressee(s) only. The unauthorised use, disclosure or copying of this e-mail, or any information it contains, is prohibited. If you are not an intended recipient, please contact the sender and delete the material from your computer. ******************************************************************************** --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]