The interesting thing is microasynchttpserver doesn't do anything substantial itself; it just reads the header data from an AsyncSocket, passes the header data to picohttpparser, and schedules the application callback with the data, to be completed via asyncdispatch. So you're essentially benchmarking picohttpparser+asyncdispatch+some minor language overhead at 200k RPS. picohttpparser was the h2o webserver's HTTP1 parser, and h2o is known to have high performance.
It would be interesting to see if the other webservers mentioned here (GuildenStern, HttpBeast, Chronos, Mummy, etc.) get a performance boost when using picohttpparser instead of their HTTP parsers.
