The Computer Language
25.02 Benchmarks Game

Java versus C++ g++

How the programs are written matters! Always look at the source code.

If the fastest programs are flagged * possible hand-written vector instructions or "unsafe" or naked ffi, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code.

fannkuch-redux      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* C++ g++ #6 3.33 13.12 5,800 1535 4.64
* C++ g++ #7 14.06 14.04—14.11 2,449 1156 2.95
C++ g++ #5 7.86 30.73—30.82 5,792 987 3.67
C++ g++ #4 8.91 34.99—35.47 5,710 1445 12.14
C++ g++ #2 9.14 35.88—36.26 5,698 1446 11.86
C++ g++ #3 37.89 37.90—37.99 2,351 600 2.70
Java #3 40.02 40.12—40.21 62,652 1264 1.69
Java 10.48 42.17—43.29 62,661 1289 1.73
C++ g++ 10.53 41.25—41.55 5,534 1065 3.88
Java #2 45.41 45.13—51.49 60,027 520 1.68
Java #8 46.66 49.88—55.68 59,994 517 1.65
n-body      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* C++ g++ #0 2.15 2.16 2,417 1933 3.66
* C++ g++ #7 4.09 4.12—4.17 5,124 1815 4.18
C++ g++ #9 5.15 5.17 2,486 1536 3.03
C++ g++ #3 5.33 5.34 2,482 1402 2.85
* C++ g++ #4 5.46 5.46 2,482 1434 2.83
* C++ g++ #2 6.02 6.02—6.10 2,490 1524 3.04
C++ g++ #5 6.33 6.35 2,478 1544 2.92
C++ g++ 6.62 6.64 2,499 1666 3.15
C++ g++ #6 6.94 6.93—6.98 2,499 1674 2.98
Java #4 6.92 6.94 60,592 1495 1.65
Java #5 7.34 7.39 61,669 1435 1.78
Java #2 7.51 7.53 60,846 1430 1.71
Java #3 7.52 7.54 61,186 1436 1.65
Java #8 7.61 7.66 60,953 1322 1.67
Java 7.89 7.91 61,276 1437 1.70
spectral-norm      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* C++ g++ #6 0.72 2.86 3,981 1050 3.08
* C++ g++ #5 1.33 5.28 5,820 1050 2.86
C++ g++ 5.34 5.34 5,292 459 3.75
Java 5.47 5.51 61,817 521 1.51
Java #8 5.47 5.51 62,308 453 1.72
Java #3 1.61 6.01 62,812 762 1.68
C++ g++ #7 1.53 6.07 4,071 1284 2.71
Java #2 1.65 6.16—6.20 61,784 956 2.76
mandelbrot      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* C++ g++ #4 0.89 3.46 37,941 3554 5.04
* C++ g++ 0.90 3.48 37,626 1797 3.59
* C++ g++ #6 0.98 3.87 37,908 1014 4.36
C++ g++ #0 2.36 9.31 38,281 2752 4.60
* C++ g++ #7 4.87 13.30 38,048 749 3.03
C++ g++ #5 13.47 13.49 36,884 596 2.76
C++ g++ #9 3.53 13.59 37,863 732 3.03
Java #2 4.16 16.30—16.44 101,253 802 1.72
Java #4 4.44 16.15—16.21 124,953 667 1.66
Java #6 4.21 16.67—17.00 100,794 808 1.78
C++ g++ #2 16.96 16.96 36,704 700 3.28
Java 24.54 24.65—24.78 60,711 671 1.81
C++ g++ #3 27.38 27.38 5,181 421 3.69
Java #8 27.72 27.85—27.91 63,836 441 1.74
Java #3 7.11 28.81—34.50 101,401 910 1.91
fasta      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
C++ g++ #9 0.78 1.56 6,214 2758 6.43
C++ g++ #2 1.85 1.85 5,108 1129 2.89
C++ g++ 1.93 1.93 5,104 1064 2.98
C++ g++ #3 2.63 2.63 5,284 1311 3.33
C++ g++ #7 0.88 3.06 6,304 2711 4.58
C++ g++ #4 3.34 3.34 2,363 1291 3.03
Java #4 3.32 3.42 62,726 1528 1.74
C++ g++ #5 1.07 3.69—3.73 7,012 2345 3.90
Java #6 1.20 3.73 68,055 2549 1.91
Java #5 1.27 3.95—4.17 68,420 2478 1.86
C++ g++ #6 1.08 3.90 7,127 2326 3.72
Java #2 4.41 4.64—4.73 65,995 1259 1.75
Java #8 10.27 10.94—11.09 202,166 894 1.99
k-nucleotide      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
C++ g++ #2 2.02 6.05—6.54 162,349 1634 7.41
C++ g++ #3 4.19 13.83—14.44 171,622 1280 5.17
C++ g++ 7.04 15.17—15.69 778,510 1452 6.55
Java 4.94 16.37—17.19 459,260 1821 2.19
Java #3 7.25 25.39—25.58 389,857 1642 2.01
Java #6 7.27 25.30—26.29 389,628 1614 2.19
Java #4 34.38 34.66—36.43 218,042 1887 2.05
Java #5 20.48 44.95—46.24 243,007 2225 2.12
Java #8 79.72 83.79—87.16 1,484,460 786 2.09
reverse-complement      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* C++ g++ #2 0.76 0.76 514,101 2099 4.30
Java #6 3.20 3.84 2,103,058 760 1.69
Java #5 4.81 4.93—5.10 1,143,575 1115 1.66
Java #4 5.73 5.87—5.94 1,958,097 656 1.58
C++ g++ 6.55 6.55—6.68 1,006,805 599 3.43
C++ g++ #5 37.66 37.65—37.69 792,846 704 3.40
Java #7   Bad Output  
C++ g++ #6   Bad Output  
C++ g++ #3   Bad Output  
Java #3   Bad Output  
binary-trees      [ Contentious. Different approaches. ]
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
C++ g++ #7 1.01 3.46—3.62 175,108 896 7.50
C++ g++ #5 1.17 4.12—4.17 208,171 891 3.87
C++ g++ #9 1.76 4.66—4.82 140,571 815 4.05
C++ g++ #6 1.93 4.90—5.09 273,973 851 4.98
C++ g++ #3 2.28 5.06—5.10 273,715 951 4.79
Java #4 4.45 5.56—5.91 1,804,603 846 2.63
C++ g++ #4 2.22 5.20—5.33 273,977 826 5.16
Java #6 4.91 5.73—5.77 1,792,643 535 1.59
Java #3 4.92 5.73—5.85 1,733,562 546 1.55
Java #2 5.05 5.84—5.91 1,792,967 558 1.78
Java #7 2.62 8.09—8.18 1,778,696 841 1.88
C++ g++ 2.69 9.43—9.52 1,896,727 760 5.34
C++ g++ #2 22.77 22.81—23.05 274,080 514 3.52
pidigits      [ Contentious. Different libraries. ]
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
C++ g++ #4 0.72 0.72 6,496 521 3.45
* C++ g++ #5 0.73 0.73 6,300 804 3.34
* Java #3 0.84 0.86 60,424 770 1.73
Java #4 1.05 1.27 78,606 733 3.62
* Java #2 1.34 1.41 65,090 944 1.71
Java 7.72 8.78—8.83 453,767 807 1.56
regex-redux      [ Contentious. Different libraries. ]
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
C++ g++ #6 1.14 2.25 285,639 2856 5.06
Java #2 1.60 3.19 386,425 2201 3.75
Java 8.45 16.81—16.98 533,582 875 1.81
Java #6 5.61 17.10—17.43 1,287,463 746 1.82
Java #3 5.30 17.04—17.22 636,994 935 1.82
C++ g++ #3 12.37 18.03—18.68 222,614 859 12.29
C++ g++   Empty  
C++ g++ #2   Empty  
C++ g++ #5   Empty  
C++ g++ #4   Empty  
Java

java 23 2024-09-17
Java HotSpot(TM) 64-Bit Server VM
(build 23+37-2369,
mixed mode, sharing)

C++ g++

g++ (Ubuntu 14.2.0-4ubuntu2) 14.2.0