Rust versus Swift

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
* 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
* Swift #3	8.20	32.45—32.61	13,722	1103	12.93
Swift #8	34.68	34.68—34.74	13,484	470	12.33
Rust #2	9.19	36.04—36.08	3,723	1198	11.14
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
* 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
* Rust #5	5.02	5.03	3,035	2224	10.61
Rust #4	5.13	4.99—5.53	3,039	1810	10.50
* Swift #3	5.45	5.44—5.48	24,928	1688	14.75
* Swift #4	5.48	5.49	24,846	1361	13.94
* Swift #5	5.52	5.50—5.55	24,928	1372	12.83
* Swift #7	5.53	5.52	24,932	1333	13.80
Rust	5.52	5.50—5.60	3,027	1483	10.84
Swift #6	5.82	5.81	12,956	1213	12.42
Swift #8	6.66	6.56—6.95	12,804	1285	12.85
Swift	7.89	7.88	12,812	1210	12.10
Swift #9	287.37	287.38—288.05	24,793	1532	13.91
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
* Rust #3	0.74	2.94	4,121	1060	10.92
Swift #8	5.36	5.35	24,859	411	14.09
Swift #3	1.45	5.71	13,689	607	12.54
* 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
* Swift #7	1.35	5.29	57,836	1147	14.15
* Swift #6	1.48	5.80	60,985	1147	14.36
Rust	2.01	7.90	42,631	874	10.94
Swift #8	25.62	25.60—25.64	12,784	426	11.26
Swift	26.55	26.54	12,780	400	12.99
Swift #5	7.27	27.13	49,312	665	13.83
* Swift #3		Bad Output
fasta
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* Rust #7	0.78	1.55	4,772	2533	11.68
Rust #3	2.03	2.03	3,199	1235	10.95
Rust #9	0.94	3.20—3.33	5,534	1952	11.24
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
Rust	4.45	4.54—4.61	3,113	1240	11.09
* Swift	5.37	5.38	12,546	1533	13.34
* Swift #3	2.20	5.37	39,002	2097	14.73
* Swift #2	3.15	5.63—5.96	13,726	1952	14.91
Swift #8	18.19	18.18—18.35	12,829	828	11.99
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
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
* Swift #2	14.45	54.24—57.70	273,949	1373	15.39
Rust	21.08	64.42—65.12	161,219	1086	12.16
Swift #8	166.95	168.68—173.38	650,023	658	14.46
Swift #7	223.40	226.91—248.09	650,023	607	13.04
Swift		Empty
reverse-complement
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* 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
* Swift	2.05	2.48	825,635	1293	14.28
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
Rust	2.10	7.44	137,417	760	11.36
Swift	18.21	54.03—54.29	763,523	720	13.97
Swift #4	17.62	54.69—59.64	733,094	772	13.31
Swift #5	18.90	56.44—56.88	764,391	813	14.89
Swift #3	18.26	58.41—58.87	733,180	868	18.46
Swift #2	18.24	58.41—58.84	732,828	822	14.89
* Swift #9		Empty
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
* 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
* Swift #2	0.76	0.75	14,459	606	12.50
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
Swift #2	39.33	39.34—39.45	710,697	678	13.66
Swift	23.92	40.23—40.37	922,243	721	13.56
Swift #4	18.21	41.75—42.40	1,102,254	751	13.30
Rust	1.84.1 (e71f9a9a9 2025-01-27) LLVM version: 19.1.5
Swift	Swift version 6.0.3 (swift-6.0.3-RELEASE) Target: x86_64-unknown-linux-gnu