[Haskell-cafe] Control.Parallel.Strategies

Hi, I was toying with the Control.Parallel.Strategies library, but can't seem to get it to actually do anything in parallel! Here's the code: import System.Random import Control.Parallel.Strategies fib :: Int -> Int fib 0 = 1 fib 1 = 1 fib n = fib (n-1) + fib (n-2) main = print $ parMap rnf fib $ take 80 $ randomRs (30,35) (mkStdGen 123) I compile with "-threaded", and run with +RTS -N2 -RTS, but yet it stays at 50% on my dual core machine! I should point out that any manual threading with forkIO does indeed use 100% of the CPU, and this problem happens on my work computer too (Vista on my home computer, XP on the work one). Anything I'm missing here? Thanks, -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862