Rust versus C clang

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 clang #6	2.25	8.88	2,941	1582	5.47
* C clang #4	13.38	13.39	2,351	1190	5.22
* 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 clang #5	8.13	32.00—32.15	4,764	917	5.37
C clang #3	34.18	34.19—34.26	2,355	574	5.02
* C clang #2	8.70	34.15—34.33	2,945	1563	5.27
Rust #2	9.19	36.04—36.08	3,723	1198	11.14
C clang #8	36.36	36.44—36.51	2,347	483	5.13
C clang	36.52	36.54—36.63	2,347	514	5.35
n-body
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* Rust #9	2.19	1.90—3.09	3,023	1881	11.01
* C clang #9	2.20	2.20	2,417	1639	6.15
* 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
* Rust #6	4.37	4.36—4.49	3,031	1796	10.86
* C clang #5	4.86	4.86	2,470	1436	5.17
* 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 clang #6	5.17	5.17	2,970	1186	5.42
C clang	5.38	5.39	2,978	1179	5.06
C clang #2	5.43	5.43	2,966	1270	5.25
Rust	5.52	5.50—5.60	3,027	1483	10.84
* C clang #4	5.60	5.61	2,953	1398	6.30
C clang #8	5.70	5.56—6.19	2,961	1195	5.27
C clang #3	6.13	6.13	2,966	1214	5.26
C clang #7	6.78	6.80	2,966	1250	5.05
spectral-norm
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C clang #6	0.39	1.55	4,686	1203	6.45
* 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
* C clang #4	0.73	2.87	5,382	1145	5.66
* C clang #5	0.73	2.87—2.91	5,403	576	5.55
* Rust #2	0.72	2.86	4,145	1117	11.00
* Rust	0.72	2.86	4,104	1262	11.75
* C clang #2	0.74	4.30—7.09	5,288	941	6.43
* Rust #3	0.74	2.94	4,121	1060	10.92
C clang #8	5.41	5.42	3,211	389	5.15
C clang #3	1.45	5.75—5.79	5,423	470	5.58
* C clang #7	1.84	8.98—10.12	5,439	906	6.66
* Rust #7		Empty
mandelbrot
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* Rust #4	0.95	3.78	35,598	1301	12.26
* 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
C clang #9	1.24	4.92	36,811	700	5.32
C clang #5	1.54	6.10	37,044	788	5.35
Rust	2.01	7.90	42,631	874	10.94
* C clang #4	3.49	13.89—13.95	36,102	805	5.26
* C clang	3.51	13.95	35,643	828	5.65
* C clang #7	3.54	14.02—14.06	36,491	1000	5.49
* C clang #3	3.56	14.16—14.20	35,418	769	5.06
C clang #8	25.51	25.52	2,359	412	5.22
* C clang #6		Empty
fasta
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
C clang #3	0.79	0.79	2,273	1469	4.57
C clang #5	1.20	1.20	2,204	1286	5.64
* Rust #7	0.78	1.55	4,772	2533	11.68
Rust #3	2.03	2.03	3,199	1235	10.95
C clang #2	2.44	2.44	2,163	1299	5.14
C clang #6	1.04	3.05	5,272	1936	5.40
Rust #9	0.94	3.20—3.33	5,534	1952	11.24
C clang #7	0.83	3.28—3.32	5,861	2276	5.29
Rust #2	0.95	3.46—3.50	5,554	1910	11.45
C clang	3.47	3.47	2,392	1213	5.28
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
Rust	4.45	4.54—4.61	3,113	1240	11.09
C clang #8	8.08	8.14—8.25	2,200	839	5.08
C clang #4		Empty
k-nucleotide
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
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 clang	6.27	13.93—14.23	134,038	1512	6.01
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 clang #7	0.45	0.61—0.67	514,220	1899	6.22
C clang #9	0.47	0.72	514,216	1551	5.13
* Rust	0.55	0.85	512,963	2762	11.72
Rust #2	1.01	1.61	1,022,128	1332	11.04
C clang #2	1.17	1.70	1,021,891	757	5.17
Rust #3	1.02	1.72	1,022,034	1105	11.45
C clang #5	1.97	2.03—2.09	1,020,813	654	5.16
* C clang #4	3.77	3.78	514,023	716	4.93
C clang #6	1.05	4.15—4.20	714,764	828	5.90
binary-trees [ Contentious. Different approaches. ]
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
Rust #5	1.07	3.84—4.01	139,121	771	1.28
Rust #2	1.17	4.16—4.25	140,157	729	12.50
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 clang #2	1.66	5.23—6.05	176,116	816	5.77
C clang #3	1.91	5.90	138,719	842	5.90
Rust	2.10	7.44	137,417	760	11.36
C clang	17.72	17.78—18.29	271,938	660	5.20
C clang #5	9.25	33.42—33.59	361,689	914	4.96
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 clang #2	0.74	0.74	3,990	422	5.19
* Rust #2	0.75	0.75	4,387	1312	10.44
* Rust	0.75	0.75	4,243	1426	10.19
C clang	0.75	0.75	3,731	459	5.35
* 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 clang #5	0.83	2.82	159,736	1403	5.40
C clang #2	3.22	3.22	106,783	1121	5.07
C clang #4	0.99	3.82—3.86	159,539	1237	5.11
C clang #3	1.76	4.34	109,867	1273	5.08
Rust	1.84.1 (e71f9a9a9 2025-01-27) LLVM version: 19.1.5
C clang	Ubuntu clang version 18.1.8 (11)