A comparison of internal timings on Bare Machine and OS-based email servers

Bare Machine (bare) email servers, which run on an ordinary PC without any commercial operating system, kernel, or other centralized support, have been shown to outperform conventional email servers that require an operating system (OS). The absence of an OS allows implementation of an email server that is lean and efficient, and able to reduce the usual communication overhead by intertwining the server application with the necessary network protocols. We identify critical points with respect to performance on a bare email server, and compare the associated internal timings with those for Java-based email servers with equivalent functionality running on Linux and Windows respectively. The results provide insight into email server operation at a protocol level, and explain the performance gains due to intertwining in the bare email server implementation. It is seen that bare email servers perform better than the OS-based servers at both the application level and the protocol level. Internal timings associated with critical server operations provide a useful means for comparing bare machine servers and their OS-based counterparts.