As somebody else stated, I wouldn't draw any conclusions from just running java -version. A couple thoughts though:
1) Java 1.4 is really pretty old. Java 6 came out in something like 2006 or 2007, IIRC. I believe Java 7 is due soon. It's unfortunate that Java doesn't do as good a job of maintaining backwards compatibility as one might like. 2) I've noted some strange and significant variations in CPU time for Java worklaods recently. I didn't try the older versions. 3) On my test system this morning, "time" shows Java -version executing in about 0.3 to 1.3s for 1.4 and 0.7 to 1.8s for Java 6. Java5 seemed to be kind of in the middle. That's on a z10 EC with zAAPs. So I'm going to say that yes, for me there might be a half second difference of elapsed time. Not sure whether that's really significant though. 4) Tuning to improve performance between releases undoubtedly would focus on real workloads, or at least workloads that should be somewhat representative of "real" workloads. If that caused a regression for the trivial workload of "java -version", I wouldn't view that as a problem. 5) Elapsed time is inherently variable, and so I generally look to the CPU time consumed to deteremine performance changes. But CPU time is getting more variable too, and especially so for Java workloads. So the rule of running multiple test iterations is all the more important today. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
