The Computer Language
Benchmarks Game

C++ g++ versus C gcc fastest programs

Back in April 2010, Russ Cox charitably suggested that only fannkuch-redux, fasta, k-nucleotide, mandlebrot, nbody, reverse-complement and spectral-norm were close to fair comparisons. As someone who implemented programming languages, his interest was "measuring the quality of the generated code when both compilers are presented with what amounts to the same program."

Differences in approach - to memory management, parallel programming, regex, arbitrary precision arithmetic, implementation technique - don't fit in that kind-of fair comparison — but we still have to deal with them.

These are only the fastest programs. There may be additional measurements for programs which seem more-like a fair comparison to you. Always look at the source code.

k-nucleotide
source secs mem gz busy cpu load
C++ g++ 3.76 156,180 1624 11.55 97% 71% 71% 69%
C gcc 5.01 130,104 1506 16.41 84% 100% 84% 59%
reverse-complement
source secs mem gz busy cpu load
C++ g++ 1.55 996,188 1226 2.66 24% 25% 99% 23%
C gcc 1.78 994,532 1438 4.02 42% 96% 46% 43%
mandelbrot
source secs mem gz busy cpu load
C++ g++ 1.50 26,324 1791 5.97 100% 99% 99% 99%
C gcc 1.65 26,204 1135 6.56 99% 100% 99% 99%
fasta
source secs mem gz busy cpu load
C++ g++ 1.33 1,824 2711 4.31 82% 82% 81% 80%
C gcc 1.36 2,912 2268 5.42 99% 100% 99% 99%
spectral-norm
source secs mem gz busy cpu load
C++ g++ 1.98 1,268 1044 7.89 100% 99% 99% 99%
C gcc 1.98 1,252 1139 7.88 99% 100% 99% 99%
pidigits
source secs mem gz busy cpu load
C++ g++ 1.89 4,460 513 1.97 100% 2% 2% 1%
C gcc 1.75 2,660 452 2.02 1% 100% 14% 1%
binary-trees
source secs mem gz busy cpu load
C++ g++ 3.79 117,164 809 12.28 99% 76% 75% 74%
C gcc 3.48 168,744 809 11.47 99% 74% 79% 79%
n-body
source secs mem gz busy cpu load
C++ g++ 8.18 1,112 1773 8.24 100% 0% 0% 1%
C gcc 7.49 8 1391 7.56 0% 0% 100% 1%
fannkuch-redux
source secs mem gz busy cpu load
C++ g++ 10.08 1,884 980 39.72 100% 100% 99% 95%
C gcc 8.61 880 910 33.96 95% 100% 99% 100%
regex-redux
source secs mem gz busy cpu load
C++ g++ 1.82 203,760 1315 4.43 44% 51% 48% 100%
C gcc 1.46 152,236 1397 3.43 43% 100% 45% 48%
C++ g++

g++ (Ubuntu 8.3.0-6ubuntu1) 8.3.0

C gcc

gcc (Ubuntu 8.3.0-6ubuntu1) 8.3.0