Java collection iteration benchmark results (JMH)

java_jmh.log

18:15:58: Executing task 'jmh'...

:compileJava NO-SOURCE
:compileGroovy NO-SOURCE
:processResources NO-SOURCE
:classes UP-TO-DATE
:compileTestJava NO-SOURCE
:compileTestGroovy NO-SOURCE
:processTestResources NO-SOURCE
:testClasses UP-TO-DATE
:compileJmhJava
:compileJmhGroovy
:processJmhResources NO-SOURCE
:jmhClasses
:jmhRunBytecodeGenerator
Processing 1 classes from /home/wololock/workspace/groovy-jmh/build/classes/java/jmh with "reflection" generator
Processing 4 classes from /home/wololock/workspace/groovy-jmh/build/classes/groovy/jmh with "reflection" generator
Writing out Java source to /home/wololock/workspace/groovy-jmh/build/jmh-generated-sources and resources to /home/wololock/workspace/groovy-jmh/build/jmh-generated-resources
:jmhCompileGeneratedClasses
:jmhJar
:jmh
# JMH version: 1.21
# VM version: JDK 1.8.0_162, Java HotSpot(TM) 64-Bit Server VM, 25.162-b12
# VM invoker: /usr/java/jdk1.8.0_162/jre/bin/java
# VM options: <none>
# Warmup: 1 iterations, 60 s each
# Measurement: 120 iterations, 1 s each
# Timeout: 10 min per iteration
# Threads: 1 thread, will synchronize iterations
# Benchmark mode: Average time, time/op
# Benchmark: bench.JavaBench.javaForEach

# Run progress: 75,00% complete, ETA 00:06:23
# Fork: 1 of 1
# Warmup Iteration   1: 8,852 ms/op
Iteration   1: 8,988 ms/op
Iteration   2: 8,816 ms/op
Iteration   3: 8,794 ms/op
Iteration   4: 8,828 ms/op
Iteration   5: 8,800 ms/op
Iteration   6: 8,850 ms/op
Iteration   7: 8,859 ms/op
Iteration   8: 8,843 ms/op
Iteration   9: 8,913 ms/op
Iteration  10: 8,803 ms/op
Iteration  11: 8,857 ms/op
Iteration  12: 8,858 ms/op
Iteration  13: 8,873 ms/op
Iteration  14: 8,849 ms/op
Iteration  15: 8,806 ms/op
Iteration  16: 8,823 ms/op
Iteration  17: 8,793 ms/op
Iteration  18: 8,821 ms/op
Iteration  19: 8,816 ms/op
Iteration  20: 8,843 ms/op
Iteration  21: 8,858 ms/op
Iteration  22: 8,856 ms/op
Iteration  23: 8,789 ms/op
Iteration  24: 8,823 ms/op
Iteration  25: 8,786 ms/op
Iteration  26: 8,847 ms/op
Iteration  27: 8,857 ms/op
Iteration  28: 8,864 ms/op
Iteration  29: 8,891 ms/op
Iteration  30: 8,862 ms/op
Iteration  31: 8,838 ms/op
Iteration  32: 8,834 ms/op
Iteration  33: 8,835 ms/op
Iteration  34: 8,794 ms/op
Iteration  35: 8,868 ms/op
Iteration  36: 8,806 ms/op
Iteration  37: 8,845 ms/op
Iteration  38: 8,787 ms/op
Iteration  39: 8,788 ms/op
Iteration  40: 8,788 ms/op
Iteration  41: 8,868 ms/op
Iteration  42: 8,822 ms/op
Iteration  43: 8,871 ms/op
Iteration  44: 8,816 ms/op
Iteration  45: 8,810 ms/op
Iteration  46: 8,859 ms/op
Iteration  47: 8,876 ms/op
Iteration  48: 8,880 ms/op
Iteration  49: 8,874 ms/op
Iteration  50: 8,865 ms/op
Iteration  51: 8,847 ms/op
Iteration  52: 8,881 ms/op
Iteration  53: 8,867 ms/op
Iteration  54: 8,868 ms/op
Iteration  55: 8,841 ms/op
Iteration  56: 8,906 ms/op
Iteration  57: 8,844 ms/op
Iteration  58: 8,833 ms/op
Iteration  59: 8,827 ms/op
Iteration  60: 8,830 ms/op
Iteration  61: 8,835 ms/op
Iteration  62: 8,852 ms/op
Iteration  63: 8,755 ms/op
Iteration  64: 8,911 ms/op
Iteration  65: 8,828 ms/op
Iteration  66: 8,866 ms/op
Iteration  67: 8,825 ms/op
Iteration  68: 8,840 ms/op
Iteration  69: 8,788 ms/op
Iteration  70: 8,864 ms/op
Iteration  71: 8,856 ms/op
Iteration  72: 8,850 ms/op
Iteration  73: 8,878 ms/op
Iteration  74: 8,839 ms/op
Iteration  75: 8,823 ms/op
Iteration  76: 8,833 ms/op
Iteration  77: 8,952 ms/op
Iteration  78: 8,831 ms/op
Iteration  79: 8,932 ms/op
Iteration  80: 8,845 ms/op
Iteration  81: 8,798 ms/op
Iteration  82: 8,841 ms/op
Iteration  83: 8,807 ms/op
Iteration  84: 8,826 ms/op
Iteration  85: 8,827 ms/op
Iteration  86: 8,837 ms/op
Iteration  87: 8,831 ms/op
Iteration  88: 8,882 ms/op
Iteration  89: 8,826 ms/op
Iteration  90: 8,816 ms/op
Iteration  91: 8,805 ms/op
Iteration  92: 8,800 ms/op
Iteration  93: 8,830 ms/op
Iteration  94: 8,815 ms/op
Iteration  95: 8,865 ms/op
Iteration  96: 8,817 ms/op
Iteration  97: 8,861 ms/op
Iteration  98: 8,798 ms/op
Iteration  99: 8,817 ms/op
Iteration 100: 8,875 ms/op
Iteration 101: 8,862 ms/op
Iteration 102: 8,788 ms/op
Iteration 103: 8,852 ms/op
Iteration 104: 8,865 ms/op
Iteration 105: 8,861 ms/op
Iteration 106: 8,835 ms/op
Iteration 107: 8,854 ms/op
Iteration 108: 8,838 ms/op
Iteration 109: 8,849 ms/op
Iteration 110: 8,803 ms/op
Iteration 111: 8,827 ms/op
Iteration 112: 8,801 ms/op
Iteration 113: 8,829 ms/op
Iteration 114: 8,778 ms/op
Iteration 115: 8,808 ms/op
Iteration 116: 8,776 ms/op
Iteration 117: 8,836 ms/op
Iteration 118: 8,802 ms/op
Iteration 119: 8,849 ms/op
Iteration 120: 8,812 ms/op


Result "bench.JavaBench.javaForEach":
  8,839 ±(99.9%) 0,011 ms/op [Average]
  (min, avg, max) = (8,755, 8,839, 8,988), stdev = 0,036
  CI (99.9%): [8,828, 8,850] (assumes normal distribution)


# JMH version: 1.21
# VM version: JDK 1.8.0_162, Java HotSpot(TM) 64-Bit Server VM, 25.162-b12
# VM invoker: /usr/java/jdk1.8.0_162/jre/bin/java
# VM options: <none>
# Warmup: 1 iterations, 60 s each
# Measurement: 120 iterations, 1 s each
# Timeout: 10 min per iteration
# Threads: 1 thread, will synchronize iterations
# Benchmark mode: Average time, time/op
# Benchmark: bench.JavaBench.javaIteratorTest

# Run progress: 87,50% complete, ETA 00:03:10
# Fork: 1 of 1
# Warmup Iteration   1: 8,854 ms/op
Iteration   1: 8,854 ms/op
Iteration   2: 8,897 ms/op
Iteration   3: 8,828 ms/op
Iteration   4: 8,873 ms/op
Iteration   5: 8,824 ms/op
Iteration   6: 8,911 ms/op
Iteration   7: 8,882 ms/op
Iteration   8: 8,864 ms/op
Iteration   9: 8,848 ms/op
Iteration  10: 9,030 ms/op
Iteration  11: 8,869 ms/op
Iteration  12: 8,888 ms/op
Iteration  13: 8,869 ms/op
Iteration  14: 8,858 ms/op
Iteration  15: 8,923 ms/op
Iteration  16: 8,829 ms/op
Iteration  17: 8,888 ms/op
Iteration  18: 8,841 ms/op
Iteration  19: 8,861 ms/op
Iteration  20: 8,859 ms/op
Iteration  21: 8,866 ms/op
Iteration  22: 8,809 ms/op
Iteration  23: 8,852 ms/op
Iteration  24: 8,853 ms/op
Iteration  25: 8,880 ms/op
Iteration  26: 8,831 ms/op
Iteration  27: 8,915 ms/op
Iteration  28: 8,830 ms/op
Iteration  29: 8,877 ms/op
Iteration  30: 8,929 ms/op
Iteration  31: 8,885 ms/op
Iteration  32: 8,844 ms/op
Iteration  33: 8,853 ms/op
Iteration  34: 8,851 ms/op
Iteration  35: 8,890 ms/op
Iteration  36: 8,835 ms/op
Iteration  37: 8,871 ms/op
Iteration  38: 8,918 ms/op
Iteration  39: 8,809 ms/op
Iteration  40: 8,878 ms/op
Iteration  41: 8,855 ms/op
Iteration  42: 8,883 ms/op
Iteration  43: 8,807 ms/op
Iteration  44: 8,880 ms/op
Iteration  45: 8,848 ms/op
Iteration  46: 8,846 ms/op
Iteration  47: 8,853 ms/op
Iteration  48: 8,863 ms/op
Iteration  49: 8,868 ms/op
Iteration  50: 8,913 ms/op
Iteration  51: 8,827 ms/op
Iteration  52: 8,883 ms/op
Iteration  53: 8,856 ms/op
Iteration  54: 8,834 ms/op
Iteration  55: 8,882 ms/op
Iteration  56: 8,888 ms/op
Iteration  57: 8,861 ms/op
Iteration  58: 8,883 ms/op
Iteration  59: 8,851 ms/op
Iteration  60: 8,820 ms/op
Iteration  61: 8,873 ms/op
Iteration  62: 8,800 ms/op
Iteration  63: 8,822 ms/op
Iteration  64: 8,816 ms/op
Iteration  65: 8,900 ms/op
Iteration  66: 8,846 ms/op
Iteration  67: 8,866 ms/op
Iteration  68: 8,897 ms/op
Iteration  69: 8,805 ms/op
Iteration  70: 8,809 ms/op
Iteration  71: 8,867 ms/op
Iteration  72: 8,868 ms/op
Iteration  73: 8,880 ms/op
Iteration  74: 8,845 ms/op
Iteration  75: 8,839 ms/op
Iteration  76: 8,837 ms/op
Iteration  77: 8,868 ms/op
Iteration  78: 8,819 ms/op
Iteration  79: 8,939 ms/op
Iteration  80: 8,853 ms/op
Iteration  81: 8,861 ms/op
Iteration  82: 8,935 ms/op
Iteration  83: 8,860 ms/op
Iteration  84: 8,875 ms/op
Iteration  85: 8,913 ms/op
Iteration  86: 8,880 ms/op
Iteration  87: 8,936 ms/op
Iteration  88: 8,867 ms/op
Iteration  89: 8,858 ms/op
Iteration  90: 8,866 ms/op
Iteration  91: 8,912 ms/op
Iteration  92: 8,821 ms/op
Iteration  93: 8,879 ms/op
Iteration  94: 8,859 ms/op
Iteration  95: 8,904 ms/op
Iteration  96: 8,852 ms/op
Iteration  97: 8,856 ms/op
Iteration  98: 8,851 ms/op
Iteration  99: 8,916 ms/op
Iteration 100: 8,841 ms/op
Iteration 101: 8,874 ms/op
Iteration 102: 8,802 ms/op
Iteration 103: 8,864 ms/op
Iteration 104: 8,811 ms/op
Iteration 105: 8,883 ms/op
Iteration 106: 8,824 ms/op
Iteration 107: 8,880 ms/op
Iteration 108: 8,853 ms/op
Iteration 109: 8,869 ms/op
Iteration 110: 8,852 ms/op
Iteration 111: 8,865 ms/op
Iteration 112: 8,872 ms/op
Iteration 113: 8,867 ms/op
Iteration 114: 8,821 ms/op
Iteration 115: 8,851 ms/op
Iteration 116: 8,833 ms/op
Iteration 117: 8,828 ms/op
Iteration 118: 8,873 ms/op
Iteration 119: 8,970 ms/op
Iteration 120: 8,890 ms/op


Result "bench.JavaBench.javaIteratorTest":
  8,865 ±(99.9%) 0,011 ms/op [Average]
  (min, avg, max) = (8,800, 8,865, 9,030), stdev = 0,036
  CI (99.9%): [8,854, 8,876] (assumes normal distribution)


# Run complete. Total time: 00:07:34

REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
experiments, perform baseline and negative tests that provide experimental control, make sure
the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
Do not assume the numbers tell you what you want them to tell.

Benchmark                                       Mode  Cnt    Score   Error  Units
JavaBench.javaForEach                           avgt  120    8,839 ± 0,011  ms/op
JavaBench.javaIteratorTest                      avgt  120    8,865 ± 0,011  ms/op

Benchmark result is saved to /home/wololock/workspace/groovy-jmh/build/reports/jmh/results.txt

BUILD SUCCESSFUL in 25m 18s
6 actionable tasks: 6 executed
18:41:17: Task execution finished 'jmh'.

from your post here, https://e.printstacktrace.blog/what-is-the-most-efficient-way-to-iterate-collection-in-groovy-jmh/
The performance diff between above in your post is not 96.422 ms vs 8.839 ms., its almost the same if you change the numbers. in the groovy code you are iterating on 10 million while in java code you iterate 1 million.

Would be great if you update your blog post to help dispel the persistent myth that groovy is slower than Java. your post comes up as #1 depending on what you search but in this search you are first (at least on mine). https://www.google.com/search?q=java+vs+groovy+iterator+performance