How many threads should I use in my Java program?

Question

I recently inherited a small Java program that takes information from a large database, does some processing and produces a detailed image regarding the information. The ori

Answer 1

After seeing your edit, it's quite possible that one thread per CPU is as good as it gets. Your application seems quite parallelizable. If you have extra hardware you can use GridGain to grid-enable your app and have it run on multiple machines. That's probably about the only thing, beyond buying faster / more cores, that will speed it up.