Ruby versus Matz's Ruby fastest programs Always look at the source code. These are only the fastest programs. Look at the other programs. They may seem more-like a fair comparison to you. fannkuch-redux source secs mem gz busy cpu load Ruby 217.08 25,628 1444 843.83 99% 99% 100% 91% Matz's Ruby 3,599.05 16,720 1444 13,876.93 95% 94% 100% 97% binary-trees source secs mem gz busy cpu load Ruby 22.04 531,952 1096 62.37 68% 89% 64% 62% Matz's Ruby 310.83 1,413,528 1096 984.39 72% 73% 71% 100% n-body source secs mem gz busy cpu load Ruby 246.88 22,032 1137 253.92 0% 1% 1% 100% Matz's Ruby 2,293.99 3,952 1137 4,696.44 78% 12% 75% 40% fasta source secs mem gz busy cpu load Ruby 30.87 71,464 1069 32.72 2% 2% 100% 3% Matz's Ruby 253.47 101,720 1071 256.95 1% 100% 0% 0% spectral-norm source secs mem gz busy cpu load Ruby 99.44 25,108 839 379.49 96% 95% 95% 95% Matz's Ruby 411.31 4,400 292 825.97 0% 100% 10% 90% k-nucleotide source secs mem gz busy cpu load Ruby 68.79 399,736 859 240.00 96% 80% 82% 91% Matz's Ruby 179.62 126,924 644 589.76 95% 69% 67% 98% reverse-complement source secs mem gz busy cpu load Ruby 9.20 2,009,456 601 18.23 75% 42% 43% 38% Matz's Ruby 21.41 492,788 264 43.01 1% 100% 0% 100% regex-redux source secs mem gz busy cpu load Ruby 9.49 277,372 724 20.85 90% 43% 38% 49% Matz's Ruby 16.43 221,312 724 48.13 100% 100% 47% 47% mandelbrot source secs mem gz busy cpu load Ruby 235.78 59,064 931 942.08 100% 100% 100% 100% Matz's Ruby 133.76 33,612 918 513.86 96% 96% 96% 96% pidigits source secs mem gz busy cpu load Ruby 1.41 303,640 485 2.50 39% 30% 10% 99% Matz's Ruby Failed Ruby ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-linux] --jit Matz's Ruby ruby 1.8.7 (2008-08-11 patchlevel 72) [x86_64-linux] So old that I haven't been able to get rubygems to work no backport, no gmp all Ruby programs & measurements all Matz's Ruby programs & measurements