I've just send a pull request[1] with an Yesod implementation.
It runs pretty well, scoring similar to webgo for the JSON pong benchmark, is almost at the same level as grails for the 1 query benchmark and is slightly faster that Play for the last benchmark.
So, Yesod is in the same performance gap as Play or Grails, and is 3~4x faster that Django or Rails.
But I've tested those on a mono-core Virtual Box, and I know Yesod scales pretty well on a multi-threaded environment.
Also, keep in mind that most of the top performing frameworks are not fully featured web framework but asynchronous I/O libraries (netty, go, nodejs, vertx, ...) which implementations just write mindlessly the raw response directly on the socket whatever the HTTP request was.
It runs pretty well, scoring similar to webgo for the JSON pong benchmark, is almost at the same level as grails for the 1 query benchmark and is slightly faster that Play for the last benchmark.
So, Yesod is in the same performance gap as Play or Grails, and is 3~4x faster that Django or Rails.
But I've tested those on a mono-core Virtual Box, and I know Yesod scales pretty well on a multi-threaded environment.
Also, keep in mind that most of the top performing frameworks are not fully featured web framework but asynchronous I/O libraries (netty, go, nodejs, vertx, ...) which implementations just write mindlessly the raw response directly on the socket whatever the HTTP request was.
[1] https://github.com/TechEmpower/FrameworkBenchmarks/pull/39