One thing to remember about the more recent Java JVMs is that each release improves its JIT compiler technology and will take advantage of the latest instructions on the machine that it runs on. Over the years, these improvements have really added up, and the latest Java SDK runs substantially better than SDK5, especially with newer machines.
Here's a recent Powerpoint presentation "A Survey of Java Performance on zEnterprise EC12" with lots of details: http://www.websphereusergroup.org/zos/go/document/download/b3ec795db12c674fc4662fc275113a69 Well written Java applications that stick to public APIs should run on new SDK releases without issues, but applications will have to be tested, which isn't fun if they don't have good regression test suites. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
