how to run more than two processes parallely

I would like to call a function called CIRCLE which is further beind called by other function but in a loop that CIRCLE fuction is being called. And this CIRCLE function starts another process which takes 3 hours to complete again, if i put that process in nohup &, I can go to the next command after completing that 3 hours process, What might be an alternative?

It's hard to say what you can do and what you can't do without seeing your code.

Will running more than two actually make it go faster? How many cores do you have? If the processes are bound by CPU speed, adding more processes than cores will just make it start sharing time, slowing down everything else and on average going no faster.

Thanks corona..
Yeah..I came to know one thing that , in a loop,i can't call a function 2 nd time until and unless the first time call got completed, This means, all the commands including the nohup & commands need to be completed....As an alternative, we can replace this function call with a script call in nohup & and we can put the ,all the code( the code in the function) in that script . ...Thanks a lot for responding to my post....