I have been using the configurations below for jdk 7 and 8 at work. 1st try: change HEAP declaration in jmeter for "-XX:+AggressiveOpts -XX:+AggressiveHeap"
2nd try: change HEAP declaration in JMeter for about 70% of available RAM, Xms and Xmx with the same value. 1st option is better suitable when using jdk 8.
