why I Need 2 processes.?
Because I need to testing the multi threading (whethther 2 threads simultaneously running )in a process.

its only one thread that can be executed at a time and time is sliced between threads.
Only one thread executed at a time is with respect to normal processor.
I m asking this situation in Multicore processor like dual core,quad core etc..
Intel is tell 2 threads is running simultaneous. you can check their demo on their website.