When you see anyone claim performance parity between <other language> and C++, one of the first things to look for is whether the C++ version of their test code is correctly using arrays and traversing them in order. If the test code is just doing equivalent pointer-chasing in both languages, the performance comparison is largely meaningless because the program is probably memory-bound and not properly written to use C++'s default container (
Note: The question below has been modified since originally posted and now shows more reasonable numbers that demonstrate contiguous arrays are indeed faster. The comments are still enlightening to read, however.
Today on SO:
Unable to reproduce: C++ Vector performance advantages over C# List performance
At Microsoft's BUILD conference Herb Sutter explained that C++ has "Real Arrays" and C#/Java languages do not have the same or sort of.
I was sold on that. You can watch the full talk here http://channel9.msdn.com/Events/Build/2014/2-661
Here is a quick snapshot of the slide where he described this. http://i.stack.imgur.com/DQaiF.png
But I wanted to see how much difference will I make.
So I wrote very naive programs for testing, [...] Here are the results on my dell laptop with Core i7 processor:count C# (List<string>) C# (ArrayList) C++ 1000 24 ms 21 ms 7 ms 10000 214 ms 213 ms 64 ms 100000 2 sec 123 ms 2 sec 125 ms 678 ms
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