title: how to do multiprocessing in java, and what speed gains to expect?
body: <p>I am a newbie using Java to do some data processing on csv files. For that I use the multithreading capabilities of Java (pools of threads) to batch-import the csv files into Java and do some operations on each of their lines. On my quad-core, multithreading speeds up the process a lot.</p>
  
  <p><strong>I am curious to know how/whether multiprocessing would speed up the operations even more? If so, is there a tutorial available somewhere?</strong> (the Java Basic Tutorial mentions a class, but I am not familiar enough with the syntax to understand the class by myself:</p>
  
  <p>from <a href="http://download.oracle.com/javase/tutorial/essential/concurrency/procthread.html" rel="noreferrer">http://download.oracle.com/javase/tutorial/essential/concurrency/procthread.html</a>:</p>
  
  <blockquote>
    <p>Most implementations of the Java virtual machine run as a single
    process. A Java application can create additional processes using a
    ProcessBuilder object. Multiprocess applications are beyond the scope
    of this lesson <strong>[where are they explained then?]</strong>.</p>
  </blockquote>