The Computer Language
25.02 Benchmarks Game

Rust 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
* Rust #6 3.81 15.15—15.33 4,137 1260 10.56
Rust #4 6.90 27.12 4,141 1026 10.29
Rust #5 7.47 29.34 3,985 1023 10.27
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
Rust #2 9.16 35.93 3,985 1198 9.94
C++ g++ #3 37.89 37.90—37.99 2,351 600 2.70
C++ g++ 10.53 41.25—41.55 5,534 1065 3.88
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
* Rust #9 2.19 1.45—4.13 3,195 1881 9.38
* Rust #7 3.24 3.24 2,937 1759 9.85
Rust #3 3.46 3.46 3,023 1774 9.16
Rust #2 3.65 3.65 3,019 1809 9.62
* C++ g++ #7 4.09 4.12—4.17 5,124 1815 4.18
* Rust #6 4.36 4.00—5.52 3,019 1796 9.37
* Rust #5 5.02 5.02 3,027 2224 9.56
Rust #4 5.13 4.74—6.21 3,019 1810 9.19
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
Rust 5.52 5.55—5.67 3,019 1483 9.35
* 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
spectral-norm      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* Rust #6 0.72 2.85 4,293 1132 10.41
Rust #4 0.72 2.85 4,014 823 10.35
* Rust #5 0.72 2.85 3,981 1062 10.56
* Rust 0.72 2.86 4,276 1262 9.73
* C++ g++ #6 0.72 2.86 3,981 1050 3.08
* Rust #2 0.73 2.86 4,264 1117 10.55
* Rust #3 0.74 2.94 4,010 1060 9.69
* C++ g++ #5 1.33 5.28 5,820 1050 2.86
C++ g++ 5.34 5.34 5,292 459 3.75
C++ g++ #7 1.53 6.07 4,071 1284 2.71
* Rust #7   Empty  
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
* Rust #4 0.95 3.78 35,955 1301 10.94
* C++ g++ #6 0.98 3.87 37,908 1014 4.36
* Rust #6 1.08 4.22 36,385 1338 10.98
Rust #2 1.10 4.34 36,016 770 11.17
Rust #5 1.12 4.38 36,549 725 11.15
Rust #7 1.11 4.38 35,934 763 10.92
Rust #3 1.15 4.57 14,008 1013 10.73
Rust 2.03 7.90 42,541 874 9.75
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
C++ g++ #2 16.96 16.96 36,704 700 3.28
C++ g++ #3 27.38 27.38 5,181 421 3.69
fasta      
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
* Rust #7 0.78 1.55 4,866 2533 10.02
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
Rust #3 1.98 1.98 2,933 1235 9.40
C++ g++ #3 2.63 2.63 5,284 1311 3.33
C++ g++ #7 0.88 3.06 6,304 2711 4.58
Rust #9 0.94 3.22—3.29 5,362 1952 9.60
C++ g++ #4 3.34 3.34 2,363 1291 3.03
Rust #5 0.94 3.33—3.44 5,505 1963 9.57
Rust #2 0.94 3.45—3.49 5,550 1910 9.74
Rust #6 3.48 3.48 128,033 959 9.00
Rust #4 3.48 3.48 128,160 944 9.04
C++ g++ #5 1.07 3.69—3.73 7,012 2345 3.90
C++ g++ #6 1.08 3.90 7,127 2326 3.72
Rust 4.49 4.51—4.55 2,990 1240 9.54
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
Rust #7 2.61 8.24—8.48 139,071 1585 12.79
Rust #3 3.24 9.47—9.81 141,701 1549 10.47
Rust #6 2.81 10.17—10.43 165,057 1697 12.99
Rust #5 3.82 11.24—11.54 143,118 1745 10.89
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
Rust #2 6.05 15.52—16.06 143,139 1350 10.31
Rust #9 6.58 17.36—18.41 140,845 1850 12.86
Rust #4 6.76 18.78—19.84 142,778 1755 11.32
Rust 21.38 65.36—66.34 159,539 1086 10.25
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
* Rust 0.54 0.85 513,090 2762 10.01
Rust #2 0.99 1.63 1,022,960 1332 10.05
Rust #3 1.00 1.73 1,022,190 1105 10.48
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
C++ g++ #6   Bad Output  
C++ g++ #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
Rust #5 1.10 3.95—4.10 137,413 771 10.93
C++ g++ #5 1.17 4.12—4.17 208,171 891 3.87
Rust #2 1.21 4.32—4.38 141,509 729 10.47
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
Rust #4 1.38 5.04—5.11 171,651 765 10.67
Rust #3 1.40 5.04—5.12 162,599 762 10.77
C++ g++ #3 2.28 5.06—5.10 273,715 951 4.79
C++ g++ #4 2.22 5.20—5.33 273,977 826 5.16
Rust 2.07 7.21—7.27 137,667 760 9.46
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
Rust #4 0.72 0.72 3,994 804 10.17
C++ g++ #4 0.72 0.72 6,496 521 3.45
* C++ g++ #5 0.73 0.73 6,300 804 3.34
* Rust 0.75 0.75 4,239 1426 9.18
* Rust #2 0.75 0.75 4,243 1312 9.19
* Rust #3 0.75 0.75 4,481 1373 9.31
regex-redux      [ Contentious. Different libraries. ]
  elapsed Mean or 95% CI      
source secs cpu secs mem gz make
Rust #6 1.18 1.43 160,154 994 11.90
Rust #5 1.34 1.58 210,186 777 10.93
Rust 1.33 1.56—1.61 160,023 811 11.14
Rust #4 1.35 1.60 206,840 771 10.94
Rust #3 1.36 1.59—1.65 210,850 726 12.52
Rust #2 1.39 1.64 160,625 707 10.84
* Rust #7 0.79 2.01 155,496 2464 11.52
C++ g++ #6 1.14 2.25 285,639 2856 5.06
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  
Rust

1.83.0
(90b35a623
2024-11-26)
LLVM version: 19.1.1

C++ g++

g++ (Ubuntu 14.2.0-4ubuntu2) 14.2.0