This is not a comparable benchmark as the sum in Smalltalk keeps on growing and ends up doing LargeInteger calculations and thus the speed loss, while the c the int just rolls over.
Sum in Smalltalk = 500000000500000000 Sum in C = -1243309312 Best regards, Henrik -----Original Message----- From: Pharo-users [mailto:pharo-users-boun...@lists.pharo.org] On Behalf Of Sven Van Caekenberghe Sent: Saturday, December 17, 2016 2:15 PM To: Any question about pharo is welcome <pharo-users@lists.pharo.org> Subject: Re: [Pharo-users] [Stupid Benchmarks] C++ vs Pharo Like this: [ | sum | sum:= 0. 1 to: 1e9 do: [ :i | sum := sum + i ]. sum ] timeToRun. "0:00:00:39.305" cat bench.c #include <stdio.h> #include <time.h> int main() { clock_t begin = clock(); int sum = 0; for (int i = 0; i < 1000000000; i++) sum += i; clock_t end = clock(); double time_spent = (double)(end - begin) / CLOCKS_PER_SEC; printf("time_spent=%f\n", time_spent); } ./a.out time_spent=2.370234 That is C being 16 times faster ... > On 17 Dec 2016, at 13:49, Sven Van Caekenberghe <s...@stfx.eu> wrote: > > Hmm, this sounds wrong (C++ should be (a lot) faster on such micro > benchmarks). > > You should exclude the executable startup time. > > In Pharo you should do [ .. ] timeToRun and something similar in C/C++. > >> On 17 Dec 2016, at 13:41, Dimitris Chloupis <kilon.al...@gmail.com> wrote: >> >> in multiplication pharo is around 2 times slower compared to C++ >> >> #include <stdio.h> >> >> int main() >> { >> double x=1; >> for(double i; i<1000000000 ; ++i) >> { >> x = 0.1*i; >> } >> >> return 1; >> } >> >> time ./testMul >> 3.13 real 3.13 user 0.00 sys >> >> time ./pharo Ephestos.image eval "|x| x := 1. 1 to: 1000000000 do:[:each| x >> := 0.1 * each]" >> 1 >> 4.97 real 4.48 user 0.09 sys >> >> On Sat, Dec 17, 2016 at 2:16 PM Dimitris Chloupis <kilon.al...@gmail.com> >> wrote: >> So I was bored and decided to test how fast pharo is compared to C++. >> >> so I tested addition >> >> C++ version: >> >> #include <stdio.h> >> >> int main() >> { >> double x=0; >> while(x<1000000000) >> { >> x = x+1; >> } >> >> return 1; >> } >> >> time ./test1 >> 2.84 real 2.84 user 0.00 sys >> >> Pharo version: >> >> time ./pharo Ephestos.image eval "|x| x := 0. 1 to: 1000000000 do:[:each| x >> := x +1]" >> 1 >> 2.09 real 1.94 user 0.08 sys >> >> Pharo is +50% faster than C++ ... o_O ... that's suprising, I assume here >> Pharo VM probably does some kind of optimisation. >> >
