The startup time on today's systems is measurable in milliseconds. It's not necessarily true that a statically loaded program will load faster -- especially as processors become faster at much faster rate than disk transfer time.

If the binary you are loading has many of it's libraries already in memory and the difference in what needs to be loaded is significant enough, the dynamically loaded version may be significantly faster than the statically loaded version.

A prime example -- perl. If you already have perl running in memory, the main perl lib is already in memory, so loading time of that 16KB segment and dynamically linking goes much faster than statically reloading 1.5MB of static code. Even a 100MB/s disk will take 15ms to read that static code. The dynamic linking of things already in memory could easily take <1ms.... Even if the libraries aren't in active memory, if they are frequently used, there is often a large disk cache on linux systems, so the file is likely already in memory... again, moving around in memory is something more on the order of microseconds than milliseconds...