Thus, if you haven't tuned your engine, you're not letting your site live up to its full potential. In many cases, you need to tune at the operating-system level as well. To enhance performance, it's important to understand the architecture of different Web-server engines. This seriously affects performance, because forking taxes a significant number of system resources. There is good news here, however.
Threads are lightweight processes that require only a fraction of the overhead of true processes.
The end result is the ability to manage more connections using the same amount of processor and memory resources. The most recent versions of both Netscape's Enterprise Server and Microsoft's IIS Web servers leverage multithreading. By contrast, NCSA servers still preallocate processes. The HTTP daemon is tunable through a number of parameters, and the default configuration installed on your site is typically not optimized. You really need to tweak the tunables to meet the needs of your environment.