Swift versus Rust fastest performance

How the programs are written matters! Always look at the source code.

If the fastest programs are * hand-written vector instructions, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code.

fannkuch-redux
source	secs	mem	gz	cpu secs
* Rust #6	3.86	19,684	1260	15.17
Rust #4	6.92	19,684	1026	27.13
Rust #5	7.45	19,684	1023	29.32
* Swift #3	8.32	19,440	1103	32.99
Swift #8	35.13	19,444	470	35.12
Rust #2	9.15	19,684	1198	35.91
n-body
source	secs	mem	gz	cpu secs
* Rust #9	2.19	19,624	1881	2.19
* Rust #7	3.23	19,624	1759	3.23
Rust #3	3.46	19,624	1774	3.45
Rust #2	3.64	19,624	1809	3.64
* Rust #6	4.36	19,624	1796	4.35
* Rust #5	5.01	19,624	2224	5.01
Rust #4	5.11	19,624	1810	5.11
* Swift #3	5.43	19,440	1688	5.43
* Swift #4	5.46	19,440	1361	5.46
* Swift #5	5.49	19,440	1372	5.49
* Swift #7	5.50	19,440	1333	5.50
Rust	5.52	19,624	1483	5.52
Swift #6	5.78	19,440	1213	5.78
Swift #8	6.65	19,440	1285	6.65
Swift	7.85	19,440	1210	7.85
Swift #9	288.23	19,440	1532	288.20
spectral-norm
source	secs	mem	gz	cpu secs
* Rust	0.72	19,632	1262	2.80
* Rust #2	0.72	19,632	1117	2.80
Rust #4	0.72	19,632	823	2.85
* Rust #5	0.72	19,632	1062	2.85
* Rust #6	0.72	19,632	1132	2.85
* Rust #3	0.74	19,632	1060	2.86
Swift #8	5.33	19,568	411	5.33
Swift #3	1.43	19,440	607	5.69
* Rust #7		Make Error
mandelbrot
source	secs	mem	gz	cpu secs
* Rust #4	0.95	33,392	1301	3.77
* Rust #6	1.07	34,152	1338	4.20
Rust #2	1.09	33,384	770	4.33
Rust #7	1.10	33,380	763	4.37
Rust #5	1.11	33,956	725	4.37
Rust #3	1.14	19,624	1013	4.54
* Swift #7	1.38	49,024	1147	5.49
* Swift #6	1.46	51,840	1147	5.78
Rust	2.00	39,404	874	7.88
Swift #8	25.59	19,492	426	25.59
Swift	26.45	19,440	400	26.45
Swift #5	7.25	43,648	665	27.03
* Swift #3		Bad Output
fasta
source	secs	mem	gz	cpu secs
* Rust #7	0.77	19,624	2533	1.54
Rust #3	1.98	19,624	1235	1.98
Rust #9	0.94	19,624	1952	3.22
Rust #5	0.93	19,624	1963	3.34
Rust #2	0.92	19,624	1910	3.40
Rust #6	3.46	123,848	959	3.46
Rust #4	3.47	123,848	944	3.46
* Swift #2	2.11	19,440	1952	3.76
Rust	4.25	19,624	1240	4.25
* Swift	5.15	19,440	1533	5.14
* Swift #3	2.18	31,248	2097	5.40
Swift #8	18.86	19,972	828	18.86
k-nucleotide
source	secs	mem	gz	cpu secs
Rust #7	2.67	133,824	1585	8.21
Rust #3	3.21	137,564	1549	9.51
Rust #6	2.80	159,764	1697	10.03
Rust #5	3.82	137,924	1745	11.17
Rust #2	5.87	138,292	1350	15.32
Rust #9	6.63	136,168	1850	17.12
Rust #4	6.73	137,308	1755	18.72
* Swift #2	14.54	260,820	1373	55.20
Rust	21.46	157,492	1086	66.75
Swift #8	181.50	627,328	658	180.87
Swift #7	233.16	627,092	607	232.52
Swift		Make Error
reverse-complement
source	secs	mem	gz	cpu secs
* Rust	0.53	498,952	2762	0.84
Rust #2	0.95	995,220	1332	1.58
Rust #3	0.97	995,156	1105	1.69
* Swift	1.95	798,228	1293	2.39
binary-trees
source	secs	mem	gz	cpu secs
Rust #5	1.09	198,720	771	3.84
Rust #2	1.19	199,796	729	4.21
Rust #3	1.39	189,928	762	5.00
Rust #4	1.39	199,084	765	5.01
Rust	2.04	132,952	760	7.26
Swift	18.28	737,152	720	54.20
Swift #8	54.90	402,048	567	54.89
Swift #4	17.49	707,456	772	55.84
Swift #5	18.89	738,048	813	56.25
Swift #2	18.29	707,456	822	58.16
Swift #3	18.18	707,584	868	58.24
* Swift #9		Make Error
pidigits
source	secs	mem	gz	cpu secs
Rust #4	0.71	19,624	804	0.71
* Rust #3	0.74	19,624	1373	0.74
* Rust #2	0.74	19,624	1312	0.74
* Rust	0.74	19,624	1426	0.74
* Swift #2	0.75	19,440	606	0.75
regex-redux
source	secs	mem	gz	cpu secs
Rust #6	1.17	153,780	994	1.42
Rust	1.34	153,972	811	1.56
Rust #5	1.33	202,800	777	1.57
Rust #4	1.34	199,684	771	1.58
Rust #3	1.34	202,952	726	1.59
Rust #2	1.38	153,932	707	1.63
* Rust #7	0.78	148,924	2464	2.00
Swift #2	38.80	686,136	678	38.80
Swift	23.40	891,792	721	39.65
Swift #4	18.30	1,064,768	751	41.36
Swift	Swift version 6.0 (swift-6.0-RELEASE) Target: x86_64-unknown-linux-gnu
Rust	1.83.0 (90b35a623 2024-11-26) LLVM version: 19.1.1