Re: [Haskell-cafe] I/O performance drop in ghc 6.12.1

On Thu, Jan 14, 2010 at 11:38 PM, Bryan O'Sullivan wrote:

On Thu, Jan 14, 2010 at 2:30 PM, Peter Simons wrote:

...

I just updated to GHC 6.12.1, and I noticed a significant drop in I/O performance that I can't explain.

This is probably brought about by the new Unicode I/O support in 6.12. Your file isn't open in binary mode, so it's probably getting translated from something like UTF-8 before it reaches you. Might want to compare the two. I'm a little surprised by the magnitude of the difference; I might have expected it to be 33%, not 400%.

Hold on, he's using hGetBuf/hPutBuf. Although I'd suggest wrapping that in bytestrings.. the point is, those functions are documented to ignore encoding and always use binary I/O. There shouldn't be a difference at all. I wonder if the difference goes away if the handle is explicitly set to binary? It shouldn't, but then again it shouldn't exist in the first place. -- Svein Ove Aas