Sort timings

	A	B	C	D	E	F	G	H	I	J	K
1	Sorting 11m strings on EC2 c4.2xlarge
2		Radix sort (ByBytes)					Quicksort
3	Max procs	Wall time (sec)	CPU time (sec)	CPU use %	% of ideal use	CPU waste %	Wall time (sec)	CPU time (sec)	CPU use %	% of ideal use	CPU waste %
4	1	10.3	10.4	100.97%	100.97%		16.5	16.64	100.85%	100.85%
5	2	6.8	10.65	156.62%	78.31%	2.40%	8.8	17.15	194.89%	97.44%	3.06%
6	4	4.7	12.13	258.09%	64.52%	16.63%	5.7	18.61	326.49%	81.62%	11.84%
7	8	3.3	12.09	366.36%	45.80%	16.25%	3.5	18.4	525.71%	65.71%	10.58%
8	16	2.7	15.3	566.67%	35.42%	47.12%	3.2	24.77	774.06%	48.38%	48.86%
9	"CPU waste %" is the total-CPU-time delta from the 1-proc sort; higher is bad. The 16 procs % may be high from using Intel's hardware threads which aren't as helpful as real cores. Unsure.
10	The data sorted is http://dumps.wikimedia.org/enwiki/20141208/enwiki-20141208-all-titles-in-ns0.gz, shuffled with sort -R. All sorts are of [][]bytes, with the file mmap'd.
11	These timings are with a slightly old revision, but should match what you'd get today--only the API has changed, not the algorithms.
12	Parallel radix sort v. parallel quicksort				Parallel radix sort v. serial quicksort				Parallel vs. serial radix sort
13	Max procs	Wall delta	CPU delta		Max procs	Wall delta	CPU delta		Max procs	Wall delta	CPU waste %
14	1	-37.58%	-37.50%		1	-37.58%	-37.50%		1	0.00%	0.00%
15	2	-22.73%	-37.90%		2	-58.79%	-36.00%		2	-33.98%	2.40%
16	4	-17.54%	-34.82%		4	-71.52%	-27.10%		4	-54.37%	16.63%
17	8	-5.71%	-34.29%		8	-80.00%	-27.34%		8	-67.96%	16.25%
18	16	-15.63%	-38.23%		16	-83.64%	-8.05%		16	-73.79%	47.12%
19	Qsort is better at keeping all cores busy, but not by quite enough to catch up to radix sort in wall time.				The radix win outweighed the parallelization costs, though total CPU time got close at 16 procs.
20
21
22	benchcmp of radixsort and stdlib sort on EC2 t2.medium
23	With -cpu=1						With -cpu=2
24	benchmark		old ns/op	new ns/op	delta		benchmark		old ns/op	new ns/op	delta
25	BenchmarkSortString1K		339428	275374	-18.87%		BenchmarkSortString1K-2		374884	298033	-20.50%
26	BenchmarkSortInt1K		147559	52741	-64.26%		BenchmarkSortInt1K-2		186007	90019	-51.60%
27	BenchmarkSortInt64K		14385182	3228304	-77.56%		BenchmarkSortInt64K-2		14367618	2535033	-82.36%
28	BenchmarkSort1e2		68821	72587	+5.47%		BenchmarkSort1e2-2		68880	72560	+5.34%
29	BenchmarkSort1e4		15154898	6455438	-57.40%		BenchmarkSort1e4-2		15175015	6700472	-55.85%
30	BenchmarkSort1e6		2395248933	701996155	-70.69%		BenchmarkSort1e6-2		2372841030	465819031	-80.37%
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100