That depends on a few things.
- Are you talking about 200 hits per second?
- How many concurrent requests can your web server provide? It'll probably queue the others. Apache by default spawns 4 to 8 listeners.
- How much memory does your script take?
- How long does your script take to execute?
- How long does it take to spawn a new interpreter process versus the time it takes your script to execute?
We can't answer any of those questions for you, but my opinion is that there are very few answers that make mod_perl or some other persistent interpreter the wrong answer.