Re: [Haskell-cafe] Is Haskell IO inherently slower than C?

Thanks for the tip! I tried it again, this time using 100000000, and the Haskell one runs at around 25 seconds. The C one is only 1.5 seconds. Can that still be the run time system? On Wed, May 4, 2016 at 9:18 PM Mike Izbicki wrote:

You need to be doing tests that take much longer to accurately compare runtimes of executables. Here's why:

Haskell programs have a more complicated run time system than C programs, and the binaries output by GHC are much larger. Therefore, there will be a small additional overhead that you have to pay once when the program starts. For some machines, this could possibly be on the order of 0.3 seconds.

I'd recommend you scale your test so that it takes at least 30 seconds for the slowest program. This will give you more meaningful results.

On Wed, May 4, 2016 at 6:07 PM, Jake wrote:

...

I also tried the more standard forM_ [0..100000] idiom and got similar times. I hoped loop might be faster, but apparently not.

On Wed, May 4, 2016 at 9:05 PM Jake wrote:

...

I'm trying to write a program in Haskell that writes a large file at the end, and it seems like that output alone is taking way longer than it should. I don't understand why Haskell shouldn't be able to write data

as

...

quickly as C, so I wrote two test files:

-- Test.hs import Control.Loop import Data.ByteString.Builder import System.IO

main :: IO () main = numLoop 0 1000000 $ \_ -> hPutBuilder stdout $ char7 ' '

// test.c #include

int main() { int i; for (i = 0; i < 1000000; i++) { fprintf(stdout, " "); } return 0; }

I compiled them both with -O2, and ran them redirecting their outputs to /dev/null. For the Haskell version I got times aroudn 0.3 seconds, while the C version was around 0.03. Is there any reason why in simple IO the Haskell version would be slower by an order of magnitude?

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe