"A tiny change in Java 8 is that Thread.stop(Throwable) is now disabled - it now throws an UnsupportedOperationException instead of working as it did in earlier Java versions. Thread.stop() still works (ie the stop() call with no argument)"
"Make sure everything is getting JIT compiled. A quick technique to check this is to switch on the -XX:+PrintCompilation flag, then redo with -XX:ReservedCodeCacheSize doubled and if more methods are getting compiled the second time, the code cache was too small"