In benchmarking some Java code on a Solaris SPARC box, I noticed that the first time I call the benchmarked function it runs EXTREMELY slowly (10x difference): First | 1 | 25295.979 ms Second | 1 | 2256.990 ms Third | 1 | 2250.575 ms Why is this? I suspect the JIT compiler, is there any wa...
Update: 2009-05-29 Thanks for all the suggestions and advice. I used your suggestions to make my production code execute 2.5 times faster on average than my best result a couple of days ago. In the end I was able to make the java code the fastest. Lessons: My example code below shows the insertion of primitive ints but the producti...
Disclaimer: I have looked through this question and this question but they both got derailed by small details and general optimization-is-unnecessary concerns. I really need all the performance I can get in my current app, which is receiving-processing-spewing MIDI data in realtime. Also it needs to scale up as well...
Hi, considering this example: public static void main(final String[] args) { final List<String> myList = Arrays.asList("A", "B", "C", "D"); final long start = System.currentTimeMillis(); for (int i = 1000000; i > myList.size(); i--) { System.out.println("Hello"); } final long stop = System.currentTimeMillis(...
First of all, this is not about the usefulness of microbenchmarks. I'm well aware of their purpose: Indicating performance characteristics and comparison in a very specific case to highlight a single aspect. Whether or not this should have any implications on your work is a different story. A few years ago, someone (I think Heinz Kabutz...
For university I benchmark the influence of certain refactorings (e.g., inline class and replace inheritance with delegation) on performance. Although I use HotSpot 5 and 6 in interpreted mode (-Xint), the differences in performance between the refactored and the not refactored versions are very small (few milliseconds at best). Therefo...