Many threads: better in one process or in several?

Question

Java

Hello! In my application, about 400 threads are planned to work simultaneously. It's a lot? Does it make sense to distribute them to different processes?

Answer 1

400 simultaneously busy threads without 400 cores will not lead to anything good,
but only greatly degrades the system. What is the task?
I would think in the direction of 4-12 working workers and a task queue.