Haskell GHC versus C clang fastest programs Always look at the source code. These are only the fastest programs. Do some of them use manually vectorized SIMD? Look at the other programs. They may seem more-like a fair comparison to you. mandelbrot source secs mem gz busy cpu load Haskell GHC 1.51 37,504 1975 5.98 99% 99% 99% 99% C clang 2.09 31,812 694 8.34 100% 100% 100% 100% fannkuch-redux source secs mem gz busy cpu load Haskell GHC 9.95 3,764 1113 39.18 95% 100% 99% 100% C clang 9.85 964 1557 37.34 90% 95% 93% 100% fasta source secs mem gz busy cpu load Haskell GHC 0.88 7,628 1882 3.32 94% 96% 93% 93% C clang 0.78 1,216 1463 0.79 0% 100% 1% 0% regex-redux source secs mem gz busy cpu load Haskell GHC 1.07 345,128 2213 2.47 59% 44% 44% 83% C clang 0.82 154,084 1397 2.80 82% 83% 79% 96% n-body source secs mem gz busy cpu load Haskell GHC 6.42 4,176 1883 6.47 0% 0% 0% 100% C clang 3.33 8 1391 3.46 1% 2% 1% 100% spectral-norm source secs mem gz busy cpu load Haskell GHC 1.47 3,964 987 5.71 97% 97% 97% 97% C clang 0.72 3,056 1139 2.87 100% 100% 100% 100% pidigits source secs mem gz busy cpu load Haskell GHC 1.64 7,792 360 2.06 9% 99% 7% 9% C clang 0.73 2,820 416 0.72 0% 99% 0% 0% binary-trees source secs mem gz busy cpu load Haskell GHC 5.02 449,868 811 18.05 90% 85% 93% 91% C clang 1.92 169,416 809 6.15 77% 79% 72% 93% k-nucleotide source secs mem gz busy cpu load Haskell GHC 22.02 638,132 1486 85.78 97% 99% 97% 97% C clang 6.01 128,788 1506 12.85 24% 44% 54% 92% reverse-complement source secs mem gz busy cpu load Haskell GHC Make Error C clang 0.99 741,472 820 3.94 100% 100% 99% 100% Haskell GHC The Glorious Glasgow Haskell Compilation System, version 9.0.1 C clang Ubuntu clang version 11.0.0-2 all Haskell GHC programs & measurements all C clang programs & measurements