JVM在并行处理方面有多好？我什么时候应该创建自己的Threads和Runnables？为什么线程会干扰？

I have a Java program that runs many small simulations. It runs a genetic algorithm, where each fitness function is a simulation using parameters on each chromosome. Each one takes maybe 10 or so seconds if run by itself, and I want to run a pretty big population size (say 100?). I can't start the next round of simulations until the previous one has finished. I have access to a machine with a whack of processors in it and I'm wondering if I need to do anything to make the simulations run in parallel. I've never written anything explicitly for multicore processors before and I understand it's a daunting task. I have a Java program that runs many small simu