MicroBench run comparing System.arraycopy with calling .clone on an array

results.out

Task Array Copying Comparisons -> Copying 100 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    23,3920
  Fastest  :     0,8380      Slowest  : 51323,3390
  95Pctile :     2,2350      99Pctile :     3,8410
  TimeBlock : 15,103 1,985 24,140 2,550 6,178 53,078 19,353 71,661 14,326 25,554
  Histogram :  3527  6359    78    12     5     1     2     0     1     3     1     0     3     3     2     3

Task Array Copying Comparisons -> Cloning 100 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    18,1080
  Fastest  :     0,8380      Slowest  : 80175,0720
  95Pctile :     2,1650      99Pctile :     4,7490
  TimeBlock : 1,897 2,136 1,495 81,781 3,189 1,250 1,277 1,175 83,622 3,265
  Histogram :  6642  3148   176    21     3     3     1     0     0     0     1     1     1     0     0     2     1

Task Array Copying Comparisons -> Copying 300 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    24,0260
  Fastest  :     0,9080      Slowest  : 58185,5310
  95Pctile :     2,7940      99Pctile :     4,1200
  TimeBlock : 27,701 12,552 1,544 82,655 10,851 1,555 2,455 63,472 35,069 2,415
  Histogram :  3432  6377   147    13     3     6     2     2     4     2     2     1     2     2     3     2

Task Array Copying Comparisons -> Cloning 300 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    27,2090
  Fastest  :     0,9080      Slowest  : 56840,4020
  95Pctile :     3,4220      99Pctile :     5,3080
  TimeBlock : 25,166 2,718 33,043 58,922 1,822 15,088 18,550 92,769 1,856 22,159
  Histogram :  2487  7050   419    22     4     3     1     0     0     0     0     2     1     5     3     3

Task Array Copying Comparisons -> Copying 500 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    36,6730
  Fastest  :     0,9080      Slowest  : 51877,8320
  95Pctile :     4,3310      99Pctile :     6,4950
  TimeBlock : 25,055 18,948 63,079 69,276 12,717 103,293 14,512 20,610 25,309 13,936
  Histogram :   709  8151  1062    33     7     8     2     2     1     1     2     3     3    11     2     3

Task Array Copying Comparisons -> Cloning 500 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    35,4540
  Fastest  :     0,9080      Slowest  : 78640,5950
  95Pctile :     3,8420      99Pctile :     5,1680
  TimeBlock : 33,438 36,611 82,758 2,062 2,263 27,903 3,671 100,427 30,849 34,560
  Histogram :   423  8842   683    22     5     4     2     1     0     0     2     1     1     6     6     1     1

Task Array Copying Comparisons -> Copying 1000 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    49,3280
  Fastest  :     1,2570      Slowest  : 67943,3960
  95Pctile :     5,7970      99Pctile :     7,6130
  TimeBlock : 42,182 123,448 43,062 17,997 128,847 3,993 65,774 16,066 19,459 32,460
  Histogram :   355  8426  1156    25     5     2     0     0     2     4     2     4     5     6     6     2

Task Array Copying Comparisons -> Cloning 1000 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    51,5940
  Fastest  :     1,2570      Slowest  : 57723,4440
  95Pctile :     5,9360      99Pctile :     9,1500
  TimeBlock : 60,024 101,436 66,544 41,199 93,536 31,879 42,019 20,345 35,645 23,321
  Histogram :   761  7503  1646    43     5     2     1     3     3     3     6     0     5    14     2     3

Task Array Copying Comparisons -> Copying 1200 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    42,8640
  Fastest  :     1,7460      Slowest  : 47815,6930
  95Pctile :     6,7050      99Pctile :    10,2670
  TimeBlock : 13,586 89,576 63,548 102,621 26,821 20,289 23,625 43,915 20,189 24,470
  Histogram :  1511  8062   370    22     6     2     1     0     4     0     1     2     9     7     3

Task Array Copying Comparisons -> Cloning 1200 elements: (Unit: MICROSECONDS)
  Count    :      10000      Average  :    42,1840
  Fastest  :     1,4670      Slowest  : 76831,4200
  95Pctile :     6,7050      99Pctile :    10,9650
  TimeBlock : 117,113 61,121 33,216 89,382 7,355 39,713 9,671 5,023 29,442 29,806
  Histogram :   356  8605   958    40    13     4     1     0     3     1     2     3     3     4     6     1

Test.java

import java.util.Random;

import net.tuis.ubench.UBench;
import net.tuis.ubench.UMode;

/**
 * Created by vogel612 on 27.09.15.
 */
public class Tests {

    private static int[] LIMITS = {100, 300, 500, 1000, 1200};
    private static final Random rng = new Random();

    public static void main (String[]args) {
        UBench bench = new UBench("Array Copying Comparisons");
        for (int limit : LIMITS) {
            final int[] sample = new int[limit];
            fillArray(sample);
            bench.addTask(String.format("Copying %d elements", limit),
              () -> {
                final int[] result = new int[sample.length];
                System.arraycopy(sample, 0, result, 0, sample.length);
                return result;
              });
            bench.addTask(String.format("Cloning %d elements", limit),
              () -> sample.clone());
        }
        bench.press(UMode.PARALLEL, 10000).report();
    }

    private static void fillArray(int[] sample) {
        for (int i = 0; i < sample.length; i++) {
            sample[i] = rng.nextInt(sample.length);
        }
    }
}