What you are missing here is the fact that I/O is orders of magnitude slower than processor. Most of the time in servers is spent waiting for I/O and multiplexi

What you are missing here is the fact that I/O is orders of magnitude slower than processor. Most of the time in servers is spent waiting for I/O and multiplexing green threads on processes without context switches while some execution paths are waiting on I/O gives you far higher capacity on the same hardware. See the other comment thread on GP comment.