Is there a way in Java to find out how many CPUs (or cores) are installed?

Question

I want to make some tuning for multithreaded program.

If I know how much threads can really work in parallel I can make the program much more effective.

Is there

Answer 1

Yes on windows for sure. JNA with kernel32.dll. Use SYSTEM_INFO structure from GetNativeSystemInfo call. There is dwNumberOfProcessors among other things.

I believe this will provide the actual number of processors installed, not the number available.