C gcc versus Classic C fastest performance Always look at the source code. If the fastest programs are hand-written vector instructions, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code. fannkuch-redux source secs mem gz cpu secs C gcc #6 2.10 11,236 1576 8.34 Classic C #6 2.22 11,248 1576 8.79 C gcc #4 14.04 11,236 1183 14.03 Classic C #4 15.53 11,244 1183 15.53 C gcc #5 7.53 11,224 910 29.37 Classic C #3 33.74 11,236 567 33.74 Classic C #5 9.05 11,160 910 35.85 Classic C #2 10.22 11,236 1557 39.51 C gcc #3 39.56 11,248 567 39.56 Classic C 40.46 11,224 508 40.46 C gcc 42.02 11,244 508 42.02 C gcc #2 11.12 11,236 1557 43.67 n-body source secs mem gz cpu secs C gcc #9 2.08 11,392 1633 2.08 Classic C #9 2.82 11,392 1633 2.82 C gcc #8 4.01 11,392 1391 4.01 C gcc #4 4.41 11,392 1490 4.41 C gcc #5 5.42 11,392 1429 5.42 Classic C #7 5.68 11,392 1244 5.68 Classic C 5.73 11,392 1173 5.73 Classic C #3 6.31 11,392 1208 6.31 Classic C #2 6.36 11,392 1263 6.36 Classic C #6 6.45 11,392 1180 6.45 C gcc #6 6.61 11,392 1180 6.60 C gcc #2 6.70 11,392 1263 6.70 C gcc 6.75 11,392 1173 6.75 C gcc #7 6.80 11,392 1244 6.80 Classic C #4 7.04 11,392 1490 7.03 C gcc #3 7.25 11,392 1208 7.25 Classic C #8 Make Error Classic C #5 Make Error spectral-norm source secs mem gz cpu secs C gcc #6 0.40 11,392 1197 1.57 Classic C #6 0.53 11,392 1197 2.11 Classic C 2.67 11,392 383 2.66 C gcc #4 0.71 11,392 1139 2.84 Classic C #5 0.71 11,392 569 2.84 C gcc #7 0.71 11,392 900 2.84 Classic C #7 0.71 11,392 900 2.84 Classic C #4 0.72 11,392 1139 2.87 C gcc #5 0.73 11,392 569 2.87 Classic C #3 0.72 11,392 463 2.88 C gcc 5.39 11,392 383 5.38 C gcc #3 1.44 11,392 463 5.70 Classic C #8 Failed C gcc #8 Make Error mandelbrot source secs mem gz cpu secs C gcc #6 1.30 32,992 1135 5.17 Classic C #8 1.53 34,980 782 6.10 C gcc #8 1.63 33,256 782 6.29 C gcc #4 3.47 32,576 799 13.86 C gcc #7 3.49 33,000 994 13.87 C gcc 3.47 32,532 822 13.88 C gcc #3 3.52 32,860 763 14.07 Classic C #9 3.63 34,364 694 14.49 C gcc #9 4.25 33,036 694 16.41 Classic C #2 24.82 11,180 406 24.82 C gcc #2 25.21 11,180 406 25.21 Classic C Make Error Classic C #6 Make Error Classic C #7 Make Error Classic C #3 Make Error Classic C #4 Make Error pidigits source secs mem gz cpu secs C gcc #2 0.81 11,392 416 0.81 Classic C #2 0.82 11,392 416 0.82 Classic C 0.88 11,392 452 0.88 C gcc 0.88 11,392 452 0.88 regex-redux source secs mem gz cpu secs C gcc #5 0.80 152,148 1397 2.02 Classic C #5 0.85 154,660 1397 2.82 C gcc #2 3.22 103,248 1115 3.22 Classic C #2 3.22 103,780 1115 3.22 C gcc #4 0.94 152,004 1230 3.26 C gcc #3 1.72 103,812 1266 3.30 Classic C #4 0.99 154,472 1230 3.87 Classic C #3 1.85 106,328 1266 4.41 fasta source secs mem gz cpu secs C gcc #9 0.78 11,284 1463 0.78 Classic C #9 1.00 11,392 1463 1.00 C gcc #5 1.30 11,392 1281 1.30 Classic C #5 1.89 11,392 1281 1.89 C gcc #6 0.94 11,392 1930 2.76 C gcc #8 2.91 11,392 1293 2.91 C gcc #4 3.07 11,392 1240 3.07 Classic C #4 3.19 11,248 1240 3.19 C gcc #2 0.81 11,392 2268 3.23 C gcc #7 0.84 11,392 2011 3.26 Classic C #6 1.19 11,284 1930 3.48 C gcc 3.72 11,392 1206 3.72 Classic C 4.02 11,288 1206 4.01 Classic C #2 1.06 11,392 2268 4.20 Classic C #7 1.09 11,392 2011 4.24 C gcc #3 4.49 11,288 819 4.49 Classic C #3 4.82 11,392 819 4.82 Classic C #8 5.01 11,392 1293 5.01 k-nucleotide source secs mem gz cpu secs Classic C 4.91 129,316 1506 9.21 C gcc 3.77 129,952 1506 12.67 reverse-complement source secs mem gz cpu secs C gcc #7 0.43 499,200 1895 0.62 Classic C #7 0.43 499,880 1895 0.63 Classic C #8 0.46 499,856 1543 0.75 C gcc #8 0.48 499,404 1543 0.80 C gcc #6 0.89 715,812 820 1.28 C gcc #5 1.46 993,848 647 1.46 Classic C #5 1.52 994,320 647 1.52 C gcc #2 1.01 993,892 750 1.52 Classic C #2 1.20 994,360 750 1.73 C gcc #4 3.68 500,380 709 3.68 Classic C #6 1.11 799,692 820 4.44 Classic C #4 4.69 500,924 709 4.69 binary-trees source secs mem gz cpu secs C gcc #2 1.57 168,448 809 4.11 C gcc #3 1.73 134,444 836 4.46 Classic C #2 1.59 170,172 809 5.10 Classic C #3 1.85 134,956 836 5.84 Classic C 17.76 264,064 654 17.75 C gcc 21.78 264,232 654 21.78 Classic C #5 7.98 351,632 908 28.65 C gcc #5 8.49 351,268 908 31.09 C gcc 12.2.0-3ubuntu1 Classic C deprecated C Intel(R) 64 Classic 2021.8.0 20221119 all C gcc programs & measurements all Classic C programs & measurements