Heap size: getRuntime().maxMemory() is much less than -Xmx parametter

Question

This is my -xmx seting in IDEA

-server
-Xms512m
-Xmx8192m
-XX:ReservedCodeCacheSize=240m
-XX:+UseConcMarkSweepGC
-XX:SoftRefLRUPolicyMSPerMB=50