Performance and scalability: calculate RAM requirements for Windows machine for java applicat

  1. HI,
    I would like to know how to calculate RAM requirement for a windows machine, I am putting a java application on it.

    I can map memory utilized in QA machine, but a production machine I have to tell how much my application will need.

    Any helpful replies appreciated.
  2. You can control the amount of memory the JVM takes using the flags -Xmx and -Xms. They specify the min and max memory the jvm is allowed to use. The actual physical memory used will be slightly more than he Xmx value specified (worst case scenario). Hope this helps
  3. If you're running on Windows then in practice you will struggle to get more than about 1.2Gb at most for the Java heap unless you're willing to start tinkering with your OS configuration and doing things like rebasing DLLs. There are plenty of articles on the net about why this limit exists and what to do about it. Maybe that doesn't help you much, but that is the upper limit you're looking at for the JVM if you're using Windows: roughly 1Gb, which is not actually very much in today's terms, certainly for server type applications. (I'm assuming it's a server app, not a desktop app.)