Thanks Adding -XX:-TieredCompilation made the run time consistent at 21ms. Still not as fast as b20 ( 5ms ) but faster than 7u4 which is 29ms. mark -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.openjdk.java.net/pipermail/mlvm-dev/attachments/20120201/76f31dee/attachment.html