I have tested as adviced by Doug to increase the initial java heap size and this is working better. The gc is effectively called once a while (but not as often as it was before). I also tried to use the -Xnoclassgc option but it does nothing.... what is the exact role of this flag ? Pascal ===================================================================== To subscribe/unsubscribe, send mail to [EMAIL PROTECTED] Java 3D Home Page: http://java.sun.com/products/java-media/3D/