Apache 2.x is a general-purpose webserver, designed to provide a balance of flexibility, portability, and performance. Although it has not been designed specifically to set benchmark records, Apache 2.x is capable of high performance in many real-world situations.
Compared to Apache 1.3, release 2.x contains many additional optimizations to increase throughput and scalability. Most of these improvements are enabled by default. However, there are compile-time and run-time configuration choices that can significantly affect performance. MPM tuning is one of the upgrades that has been made in apache 2.x.
Linux Guru 