I've personally observed huge boosts in the number of concurrent connections a machine can handle with Apache-worker vs Apache-prefork. I've personally observed PHP applications going into fairly high CPU use, and then settling down a lot once I installed APC (which prevents the machine from having the parse the PHP on every request). It's not conjecture, it's observation. I also know that due to the nature of how .NET apps work, they never have that kind of problem. Neither do most other modern web frameworks. Sorry I don't have the graphs-- I don't use Microsoft apps any more. Good day!