Can someone comment on the Debian package for Ubuntu Hoary providing ghc-6.2.2 with binary for amd64? I'm asking because I'm unexpectedly getting really bad performance as you can see here: http://felix.sourceforge.net/current/speed/en_flx_perf_0005.html and here: http://felix.sourceforge.net/current/speed/en_flx_perf_0011.html These links are unstable, this one should always have the latest results: http://felix.sourceforge.net/current/speed/en_flx_perf.html The compilation is using: ghc -O3 -fvia-C -optc -O3 which can probably be tweaked, any advice on that appreciated. The actual test script measures real time performance by running programs at random.. there are lots of samples, the graphs are statistically reliable, and the randomness should eliminate most biases. For ackermann, the test is actually measuring how many words are required in the stack per call: the more the slower. For takfp, ghc is way behind, and Ocaml is actually way ahead since I think it uses doubles where the C based systems are using single precision (this affects the size of a stack frame) .. not sure about ghc, is Float a C float or a double in ghc? I may try to build from source if this is expected to provide better performance. -- John Skaller <skaller at users dot sourceforge dot net> Download Felix: http://felix.sf.net