I have placed constraint on version of hashable, time is exactly same.
bmaxa@maxa:~/shootout/knucleotide$ cabal list hashable
* hashable
Synopsis: A class for types that can be converted to a hash value
Default available version: 1.2.0.5
Installed versions: 1.1.2.5
Homepage: http://github.com/tibbe/hashable
License: BSD3
Date: Sun, 24 Mar 2013 20:12:57 +0100
Subject: Re: [Haskell-cafe] my take at knucleotide
From: greg@gregorycollins.net
To: bmaxa@hotmail.com
CC: haskell-cafe@haskell.org
What happens to performance if you compile and link with "cabal install --constraint='hashable < 1.2'" ?
G