Something to Remember, Java is a Byte Code (two bytes actually) interpretive language, where the byte code corresponds to a Machines Instruction on the Virtual CPU.
When a compiled Java program runs, it still must interpret the Byte Code into the actual CPU's Byte Code, then process the instruction. The Byte Code set of Java includes Virtual Machine Instructions that may not have a counterpart on various real CPU's, these have to be translated into a series of real machine instructions that give the results expect. Additionally in the case of primitive integers, Java has to switch them from Little Endian to Big Endian before sending the CPU instruction, than back after the instruction is done. No matter how much you try and tune Java, or listen to Java Only folks explain that it's just as fast. It simply is not, at best it is only marginally faster then running REXX in interpretive mode. The same program in COBOL, C, or Assembler will out perform Java from 10 times to hundreds of times faster, and use a heck of a lot less CPU cycles. This is one of the main reasons to avoid Java, especially if you are in a shop that bills out CPU Cycles. Darren >Does anyone have any tuning/performance references/links for Java under z/OS? > >Some tentative footsteps were taken to develop Java apps to run under USS and the "Hello World" app sucked down 30% of the CPU during the time the app was running. :( So, I gotta prepare for the onslaught when things really kick into high gear. > >Thanks. ---------------------------------------------------------------------- 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
