I have below memory options configured : export MEM_OPTS="-Xmx2560m -Xms2560m -XX:NewSize=786m -XX:MaxNewSize=786m -XX:+UseTLAB -XX:MaxPermSize=512m" GC parameters are as below : export GC1_OPTS="-XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:**CMSInitiatingOccupancyFraction=50** -XX:+CMSPermGenSweepingEnabled -XX:+CMSClassUnloadingEnabled -XX:+CMSParallelRemarkEnabled -XX:+UseAdaptiveGCBoundary" export GC2_OPTS="-XX:+ExplicitGCInvokesConcurrent" I would like to know, When CMS will run.Will it run after 50% of 2560 MB or Will it run after 50% of 512 MB of memory. What is the concept ? My total Heap memory would be = 2560+786+512 MB.... right ? or "-XX:NewSize=786m -XX:MaxNewSize=786m" is for NON Heap.Please explain the concept.