Warning..sarcasm alert....... And how is this better than good old COBOL and ASSEMBLER???
Sarcasm alert off......... Glenn Glenn A. Schneck AVP, Transaction Services SunTrust Banks, Inc. Tel: 407-762-3514 Mobile: 407-625-2596 Normal Business Hours - 7 AM - 4PM Eastern Time Office - Monday, Tuesday, Friday WFH - Wednesday, Thursday Live Solid. Bank Solid. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Scott Chapman Sent: Wednesday, July 13, 2011 7:33 AM To: [email protected] Subject: Re: performance differences between java versions 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 LEGAL DISCLAIMER The information transmitted is intended solely for the individual or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of or taking action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you have received this email in error please contact the sender and delete the material from any computer. SunTrust is a federally registered service mark of SunTrust Banks, Inc. Live Solid. Bank Solid. is a service mark of SunTrust Banks, Inc. [ST:XCL] ---------------------------------------------------------------------- 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
