no, the most common bottlenecks are

• access to FS to read file
• compilation time at start-up

do FILE can't solve this, only pre-compiling all scripts and keeping them in memory, the way modperl or FCGI do.

Although first step should be a thorough analysis where the performance is lost.°

Worst-case would be that you'll need to expand to a multi-server farm.

°) sometimes a RAM disk is the easiest solution.

update

I missed the info about the pre-froking. see Re^4: Use of do() to run lots of perl scripts for more