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Comment by alayne | Hacker News Reader

Java's performance relative to other commonly used languages is very good. It's basically been at 2-3x slower than C/C++ for quite a while.

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2-3x slower? I guess it depends on what you're doing. For a lot of code I've dealt with the differences in performance have been factional.

Only computation-heavy code will show a difference. And the disparity is going to vary a lot. Some code will be easy for Java's optimizer and won't give C++ any advantage.

Some will even put C++ at a disadvantage.

Out of curiosity any such examples ?

Of course there are, and it only takes a few seconds with Google to find them. Here's one: the frannkuch-redux benchmark at http://benchmarksgame.alioth.debian.org/u64q/java.php gives Java a >20% CPU efficiency advantage over C++.

That compares a Java program written to use multiple cores with a C++ program not written to use multiple cores; because the C++ programs written to use multiple cores did not compile.

See http://benchmarksgame.alioth.debian.org/u64q/performance.php...

This doesn't make much sense, unless:

1) You wrote that code in BOTH Java and C++, optimized both, and compared their running times.

2) Said code was CPU bound. For heavy IO bound code you could even use TCL and get "fractional" differences.

It is very good. But it's not quite fair to compare it to, say ruby or PHP, because it still requires a compilation step, and it's still pretty demanding on the programmer.

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