Optimise my ray tracer - comp.lang.java.programmer

Message from discussion Optimise my ray tracer

Jon Harrop

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More options 11 Jun 2005, 13:03

Newsgroups: comp.lang.java.programmer

From: Jon Harrop <use...@jdh30.plus.com>

Date: Sat, 11 Jun 2005 13:03:02 +0100

Local: Sat 11 Jun 2005 13:03

Subject: Re: Optimise my ray tracer

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Tor Iver Wilhelmsen wrote:
> Jon Harrop <use...@jdh30.plus.com> writes:
>> Can you elaborate on this? All of my tests indicate that Java is many
>> times slower than most other modern languages, even stereotypically slow
>> languages like SML and OCaml.

> Since Java code (unless forced to run interpreted) runs 98% of its
> time as run-time optimized native code, how can it be slower than
> compile-time optimized C code?

Many possible reasons:

1. Java's optimiser isn't as good.
2. The time spent optimising is longer than the time saved executing.
3. Deficiencies in the language (of which there are many in Java, e.g.
run-time checks due to OO, boxing).
4. Poor implementations of performance critical constructs by the compiler,
e.g. recursion.

> Are you perchance taking startup time into consideration?

I have taken startup time into consideration. Java is still consistently
many times slower than most other languages.

--
Dr Jon D Harrop, Flying Frog Consultancy
http://www.ffconsultancy.com

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