C++ g++ versus Java

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
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
* C++ g++ #6	3.33	5,800	1535	4.64	13.12
* C++ g++ #7	14.06	2,449	1156	2.95	14.04—14.11
C++ g++ #5	7.86	5,792	987	3.67	30.73—30.82
C++ g++ #4	8.91	5,710	1445	12.14	34.99—35.47
C++ g++ #2	9.14	5,698	1446	11.86	35.88—36.26
C++ g++ #3	37.89	2,351	600	2.70	37.90—37.99
Java #3	40.03	62,276	1264	1.93	39.96—40.70
Java	10.50	62,824	1289	1.76	42.15—43.19
C++ g++	10.53	5,534	1065	3.88	41.25—41.55
Java #2	45.42	60,305	520	1.59	46.60—54.76
Java #8	46.67	60,162	517	1.65	52.08—57.09
n-body
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
* C++ g++ #0	2.15	2,417	1933	3.66	2.16
* C++ g++ #7	4.09	5,124	1815	4.18	4.12—4.17
C++ g++ #9	5.15	2,486	1536	3.03	5.17
C++ g++ #3	5.33	2,482	1402	2.85	5.34
* C++ g++ #4	5.46	2,482	1434	2.83	5.46
* C++ g++ #2	6.02	2,490	1524	3.04	6.02—6.10
C++ g++ #5	6.33	2,478	1544	2.92	6.35
C++ g++	6.62	2,499	1666	3.15	6.64
C++ g++ #6	6.94	2,499	1674	2.98	6.93—6.98
Java #4	6.92	60,936	1495	1.76	6.94
Java #5	7.34	61,641	1435	1.63	7.39
Java #2	7.51	60,588	1430	1.66	7.53
Java #3	7.53	60,764	1436	1.65	7.54
Java #8	7.62	61,059	1322	1.65	7.66
Java	7.89	61,207	1437	1.64	7.91
spectral-norm
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
* C++ g++ #6	0.72	3,981	1050	3.08	2.86
* C++ g++ #5	1.33	5,820	1050	2.86	5.28
C++ g++	5.34	5,292	459	3.75	5.34
Java	5.47	61,923	521	1.65	5.51
Java #8	5.47	62,214	453	1.66	5.51
Java #3	1.61	62,992	762	1.70	6.02
C++ g++ #7	1.53	4,071	1284	2.71	6.07
Java #2	1.64	61,846	956	1.69	6.19
mandelbrot
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
* C++ g++ #4	0.89	37,941	3554	5.04	3.46
* C++ g++	0.90	37,626	1797	3.59	3.48
* C++ g++ #6	0.98	37,908	1014	4.36	3.87
C++ g++ #0	2.36	38,281	2752	4.60	9.31
* C++ g++ #7	4.87	38,048	749	3.03	13.30
C++ g++ #5	13.47	36,884	596	2.76	13.49
C++ g++ #9	3.53	37,863	732	3.03	13.59
Java #4	4.43	125,346	667	1.85	16.14—16.20
Java #2	4.17	100,966	802	1.70	16.33—16.47
Java #6	4.23	101,396	808	1.78	16.65—16.80
C++ g++ #2	16.96	36,704	700	3.28	16.96
Java	24.55	60,981	671	1.74	24.60—24.73
C++ g++ #3	27.38	5,181	421	3.69	27.38
Java #8	27.72	63,488	441	1.63	27.85—27.90
Java #3	7.12	101,405	910	1.66	30.67—35.89
fasta
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
C++ g++ #9	0.78	6,214	2758	6.43	1.56
C++ g++ #2	1.85	5,108	1129	2.89	1.85
C++ g++	1.93	5,104	1064	2.98	1.93
C++ g++ #3	2.63	5,284	1311	3.33	2.63
C++ g++ #7	0.88	6,304	2711	4.58	3.06
C++ g++ #4	3.34	2,363	1291	3.03	3.34
Java #4	3.32	62,530	1528	1.71	3.44
C++ g++ #5	1.07	7,012	2345	3.90	3.69—3.73
Java #6	1.20	68,858	2549	1.89	3.73
C++ g++ #6	1.08	7,127	2326	3.72	3.90
Java #5	1.27	68,436	2478	1.89	4.00—4.17
Java #2	4.49	63,721	1259	1.86	4.68—4.72
Java #8	10.26	202,498	894	1.75	10.97—11.26
k-nucleotide
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
C++ g++ #2	2.02	162,349	1634	7.41	6.05—6.54
C++ g++ #3	4.19	171,622	1280	5.17	13.83—14.44
C++ g++	7.04	778,510	1452	6.55	15.17—15.69
Java	4.95	395,911	1821	2.18	16.20—17.07
Java #3	7.34	440,570	1642	2.09	25.33—26.04
Java #6	7.33	440,021	1614	2.04	25.38—26.07
Java #4	34.47	219,398	1887	2.03	34.92—35.12
Java #5	15.99	242,340	2225	2.25	41.77—45.84
Java #8	80.18	1,478,750	786	2.25	84.45—86.62
reverse-complement
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
* C++ g++ #2	0.76	514,101	2099	4.30	0.76
Java #6	3.23	2,102,866	760	1.77	3.86
Java #5	4.81	1,143,628	1115	1.68	4.92—5.03
Java #4	5.77	1,956,815	656	1.51	5.90—5.94
C++ g++	6.55	1,006,805	599	3.43	6.55—6.68
C++ g++ #5	37.66	792,846	704	3.40	37.65—37.69
Java #7		Bad Output
C++ g++ #6		Bad Output
C++ g++ #3		Bad Output
Java #3		Bad Output
binary-trees
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
C++ g++ #7	1.01	175,108	896	7.50	3.46—3.62
C++ g++ #5	1.17	208,171	891	3.87	4.12—4.17
C++ g++ #9	1.76	140,571	815	4.05	4.66—4.82
C++ g++ #6	1.93	273,973	851	4.98	4.90—5.09
C++ g++ #3	2.28	273,715	951	4.79	5.06—5.10
C++ g++ #4	2.22	273,977	826	5.16	5.20—5.33
Java #4	4.55	1,848,893	846	1.84	5.55—5.91
Java #6	4.88	1,587,278	535	1.66	5.70—5.81
Java #3	4.84	1,661,899	546	1.59	5.65—5.74
Java #2	5.06	1,738,625	558	1.59	5.88—5.97
Java #8	6.56	1,640,554	596	1.62	7.30—7.37
Java #7	2.64	1,787,023	841	1.81	8.18—8.24
C++ g++	2.69	1,896,727	760	5.34	9.43—9.52
C++ g++ #2	22.77	274,080	514	3.52	22.81—23.05
pidigits
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
C++ g++ #4	0.72	6,496	521	3.45	0.72
* C++ g++ #5	0.73	6,300	804	3.34	0.73
* Java #3	0.84	60,092	770	1.82	0.84
* Java #2	1.33	64,795	944	1.62	1.39
Java	7.72	423,662	807	1.76	8.77—8.81
regex-redux
	elapsed				Mean or 95% CI
source	secs	mem	gz	make	cpu secs
C++ g++ #6	1.14	285,639	2856	5.06	2.25
Java	8.50	532,001	875	1.73	16.76—16.99
Java #6	5.63	1,287,786	746	1.95	17.15—17.44
Java #3	5.33	643,936	935	1.97	17.06—17.25
C++ g++ #3	12.37	222,614	859	12.29	18.03—18.68
C++ g++		Empty
Java #2		Bad Output
C++ g++ #2		Empty
C++ g++ #5		Empty
C++ g++ #4		Empty
C++ g++	g++ (Ubuntu 14.2.0-4ubuntu2) 14.2.0
Java	java 23 2024-09-17 Java HotSpot(TM) 64-Bit Server VM (build 23+37-2369, mixed mode, sharing)