We tried different parametrs of GC and tested them too finally we are with the following GC params(as it is giving good TPS with minimal pause time of app).
JAVA_OPTS="$JAVA_OPTS -Xmx4096m -Xms4096m -Xmn2g -Xss128k -XX:ParallelGCThreads=8 -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:SurvivorRatio=8 -XX:TargetSurvivorRatio=90 -XX:MaxTenuringThreshold=31 -XX:MaxPermSize=512m -XX:PermSize=256m
But we didnt find any drop/increase in CPU utilization with all the test we performed with different combination and different type of GC collector.