bulat.ziganshin: > Hello Simon, > > Monday, July 10, 2006, 1:12:13 PM, you wrote: > > >> numerical speed is poor in ghc 6.4, according to my tests. it's 10-20 > >> times worse than of gcc. afair, the mandelbrot benchmark of Great > >> Language Shootout proves this - despite all optimization attempts, > >> GHC entry is still 5-10 times slower than gcc/ocaml/clean ones > > > We average 1.3x slower than C in the shootout. Thanks to Don Stewart for > > the following stats... > > as i once wrote, most of shootout benchmarks depends on the libs. for > example, multi-threading benchmark is much faster on GHC than on GCC > because former has user-level threads support pre-included and for > later the external libs should be used (testing policy prohibits using > of additional libs) > > > The numerical floating-point-intensive benchmarks: > > > mandelbrot 2.7x C (Clean 1.7x, OCaml 2.4x, C++ 2.6x) > > n-body 2.1x C (Clean 0.9x, OCaml 1.3x, C++ 1.4x) > > that is the benchmarks that i had in mind > > > http://shootout.alioth.debian.org/gp4/benchmark.php?test=mandelbrot&lang=all > > the same benchmark with N=600 and Sempron processor: > > http://shootout.alioth.debian.org/debian/benchmark.php?test=mandelbrot&lang=all > > here GHC is 10x slower than GCC and more than 5 times compared to > Clean and Ocaml. i think that this is the real computing speed > difference while with N=2000 C/Ocaml/Clean programs was really limited > by memory speed.
Ah! In this case, on the debian, the benchmark has been compiled _without_ -fexcess-precision, that's what's causing the big slow down. We had to turn it on, on the gp4, but it seems the flag wasn't propagated to the debian/sempron builds for some reason. Looks like the ghc/mandelbrot benchmarks just needs to be rerun with -fexcess-precision in this case. -- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe