C++ g++ versus Rust

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	15.06	3,985	1260	11.92
Rust #4	6.94	27.12	3,985	1026	11.71
Rust #5	7.41	28.89	3,990	1023	11.79
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	9.19	36.04—36.08	3,723	1198	11.14
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	1.90—3.09	3,023	1881	11.01
* Rust #7	3.24	3.24	2,937	1759	10.53
Rust #3	3.46	3.46	2,937	1774	10.62
Rust #2	3.65	3.65	3,031	1809	10.49
* C++ g++ #7	4.09	4.12—4.17	5,124	1815	4.18
Rust #6	4.37	4.36—4.49	3,031	1796	10.86
* Rust #5	5.02	5.03	3,035	2224	10.61
Rust #4	5.13	4.99—5.53	3,039	1810	10.50
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	5.50—5.60	3,027	1483	10.84
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	3,981	1132	12.60
Rust #4	0.72	2.85	4,047	823	12.00
Rust #5	0.72	2.86	4,018	1062	11.30
* Rust #2	0.72	2.86	4,145	1117	11.00
* Rust	0.72	2.86	4,104	1262	11.75
* C++ g++ #6	0.72	2.86	3,981	1050	3.08
* Rust #3	0.74	2.94	4,121	1060	10.92
* 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	35,598	1301	12.26
* C++ g++ #6	0.98	3.87	37,908	1014	4.36
Rust #6	1.08	4.21	36,426	1338	12.65
Rust #7	1.10	4.34	35,906	763	12.32
Rust #2	1.10	4.36—4.52	35,754	770	12.80
Rust #5	1.12	4.38	36,311	725	12.27
Rust #3	1.15	4.57	14,615	1013	12.66
Rust	2.01	7.90	42,631	874	10.94
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	4,772	2533	11.68
* 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	2.03	2.03	3,199	1235	10.95
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	3.20—3.33	5,534	1952	11.24
C++ g++ #4	3.34	3.34	2,363	1291	3.03
Rust #2	0.95	3.46—3.50	5,554	1910	11.45
Rust #5	0.94	3.48—3.53	5,554	1963	12.19
Rust #4	3.52	3.53	128,217	944	10.63
Rust #6	3.53	3.53	128,381	959	10.62
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	4.45	4.54—4.61	3,113	1240	11.09
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	2.57	8.13—8.39	139,088	1585	13.43
Rust #3	3.28	9.72—10.13	142,631	1549	11.91
Rust #6	2.79	10.06—10.15	165,048	1697	14.10
Rust #5	3.88	11.66—11.92	143,155	1745	12.40
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	6.00	15.71—16.24	142,946	1350	11.85
Rust #9	6.33	17.72—18.82	141,099	1850	14.41
Rust #4	6.69	18.00—18.74	142,090	1755	13.13
Rust	21.08	64.42—65.12	161,219	1086	12.16
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	0.55	0.85	512,963	2762	11.72
Rust #2	1.01	1.61	1,022,128	1332	11.04
Rust #3	1.02	1.72	1,022,034	1105	11.45
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	1.07	3.84—4.01	139,121	771	1.28
C++ g++ #5	1.17	4.12—4.17	208,171	891	3.87
Rust #2	1.17	4.16—4.25	140,157	729	12.50
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	4.98—5.02	202,686	765	12.32
Rust #3	1.40	5.15—5.26	172,392	762	11.90
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	2.10	7.44	137,417	760	11.36
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	0.71	0.72	4,055	804	11.82
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 #2	0.75	0.75	4,387	1312	10.44
* Rust	0.75	0.75	4,243	1426	10.19
* Rust #3	0.75	0.75	4,510	1373	10.10
regex-redux [ Contentious. Different libraries. ]
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
Rust #6	1.21	1.46	159,846	994	13.12
Rust #5	1.35	1.58	209,863	777	12.67
Rust	1.35	1.59—1.63	159,793	811	12.22
Rust #3	1.38	1.63	210,379	726	13.51
Rust #4	1.38	1.64	206,811	771	12.41
Rust #2	1.38	1.64	159,937	707	11.67
* Rust #7	0.78	2.00	157,442	2464	12.48
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
C++ g++	g++ (Ubuntu 14.2.0-4ubuntu2) 14.2.0
Rust	1.84.1 (e71f9a9a9 2025-01-27) LLVM version: 19.1.5