“Many of the test cases in the original language shootout involved calculation or large values in loops, which would cause Perl and Python (and even C, Java, and C++) to chug merrily away burning cycles so that I could measure the timings in seconds, rather than microseconds. Then along came GHC, and the lazy nature of the evaluation threw out the unneeded calculations, handing over the final useful result without breaking a sweat.

Consequently, we had to revise many of the tests to force the programs to perform real work. With those changes, Haskell began to fall back in speed to more moderate levels. However, in the last few releases, GHC has approached native C in performance overall.

The performance is also consistent across platforms. [For example] While Java’s HotSpot compiler makes a good showing on Intel, my AMD test machine yields consistently worse results. However, GHC performs equally well on both systems. This is great because applications written in Haskell can be reasonably expected to yield good performance on all of the common x86 platforms without customizations.