We'd be delighted if someone offered a more performant library to put into future GHC releases. Simon | -----Original Message----- | From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Don | Stewart | Sent: 13 October 2007 22:38 | To: Isaac Dupree | Cc: haskell-cafe@haskell.org | Subject: Re: [Haskell-cafe] Performance problem with random numbers | | isaacdupree: | > ntupel wrote: | > >Thanks for your reply Stefan. Unfortunately I could measure only a | > >relatively small improvement by changing to concrete types | > | > >the sample code was about one second faster when compiled with -O2. | > >Profiling again indicated that most time was spend in random and randomR | > | > GHC StdGen's random and randomR are somewhat slow. I found that | > changing to a custom ((x*a + b) `mod` c) random-generator (instance of | > RandomGen) much sped things up (since nothing depended on the random | > numbers being good quality). (Then I switched to a small C function to | > do the randomization and make all the OpenGL calls, and it sped up by | > another factor of 4.) | > | | I've seen similar results switching to the SIMD mersenne twister C | implementation for randoms: | | http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html | | If there's interest, I can package up the bindings for hackage. | | -- Don | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe@haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe