Hello haskell-cafe, since there are no objective tests comparing ghc to gcc, i made my own one. these are 3 programs, calculating sum in c++ and haskell: main = print $ sum[1..10^9::Int] main = print $ sum0 (10^9) 0 sum0 :: Int -> Int -> Int sum0 0 !acc = acc sum0 !x !acc = sum0 (x-1) (acc+x) main() { int sum=0; //for(int j=0; j<100;j++) for(int i=0; i<1000*1000*1000;i++) sum += i; return sum; } execution times: sum: ghc 6.6.1 -O2 : 12.433 secs ghc 6.10.1 -O2 : 12.792 secs sum-fast: ghc 6.6.1 -O2 : 1.919 secs ghc 6.10.1 -O2 : 1.856 secs ghc 6.10.1 -O2 -fvia-C : 1.966 secs C++: gcc 3.4.5 -O3 -funroll-loops: 0.062 secs -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com