From: Charles D Hixson <charleshixsn@...>
Date: 2006-11-21T06:56:46+09:00
Subject: Re: Ruby vs Java vs c++

Roseanne Zhang wrote:
> El Gato wrote:
>   
>> Ruby and the speed of C++.  Welcome to the club.  Strangely enough, 
>> Java's domain really is somewhere between each.  Plus, you'll never 
>> truly appreciate a language like Ruby until you deal with a more... 
>> verbose language such as Java.
>>     
>
> Everybody here or somewhere else take that for granted: Java is slower 
> than C++, but actually that is not true.
>
> I thought so too. However, my computational heavy practice proved, to 
> certain extent, otherwise.
>
> Interesting enough, I was a very experienced C++ programmer, and 
> learning Java in 2000. I got an very heavy algorithm job. I write the 
> same code in Java and C++. When the algorithm was relatively simple, my 
> C++ code was about twice faster than Java c++/Java = 610/1085. However, 
> when my algorithm became extremely heavy iteration, the result was 
> c++/Java = 26000/12000. Java was more than twice faster than C++.
>
> I asked several Java experts include Jason Hunter, Daniel Brookshier 
> about the question, why? The answers are the same, JIT!!!!
>   
Your answer is processor cache relative.  It also depends on how well 
the C++ optimizer works. 
OTOH, D (Digital Mars D) also turns in times faster than C++...probably 
for similar reasons. And it's a compiled language.  Theoretically, with 
a good optimizer, this should be impossible...so I suspect the C optimizer.