As said in your other post, there is no fixed answer. The best way to
get an answer for your system is the write a small test program
spawning threads, until the system breaks.

public class ThreadSpawn implements Runnable {
   public static void main(String[] args) {
       for (int x = 1; x < Integer.MAX_VALUE; x++) {
           System.out.println("Spawning thread " + x);
           new Thread(new ThreadSpawn()).start();
       }
   }

   public void run() {
       try {
           Thread.sleep(Integer.MAX_VALUE);
       } catch (InterruptedException e) {
           e.printStackTrace();
       }
   }
}

Shut down as much processes as possible on your system and run this
program. This will give you a rough answer. Mine broke after 7122
threads.

Regards,

Bart