How powerful is a Celeron 667MHz processor, compared to a RaQ4i (AMD K-6 450MHz)? How many times more hits per second do you think it could handle for mod_perl scripts?

The main issue here will be RAM. Of course a faster CPU should pump out more pages, but most of the time, I find that CPUs rarely get overloaded unless you have a lot of traffic and all generated by a database. I would go fo at least 256MB if not 512MB of RAM.

Another issue is if you are using databases on high-volume sites -- check your SQL statements and database configuration. SQL is very good (fast) at some things and bad at others (slow). For example, SQL can do basic math quite quickly but more complex or longer math operations may be better moved into your script logic. SQL is also very good at simple sorting. Small changes like these can have a huge impact on server performance.


The bottom line is that you can never tell if a server is performing well into it is in production -- benchmark testing can help but can rarely simulate real traffic.