From: Robert Klemme <shortcutter@...>
Date: 2006-05-23T16:10:55+09:00
Subject: Re: Zed and Luis drop the bomb on Ruby's poor performance

2006/5/22, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov>:
> On Tue, 23 May 2006, James Britt wrote:
>
> > ara.t.howard@noaa.gov wrote:
> >
> >> ... you make good points - but let me just throw in my 2 cts:
> >>
> >> virtual machines are stupid.  java is slow.  c++ is slow.  python is slow.
> >> ruby is slow.  so what.  if you want fast you need c or fortan or
> >> assembler.
> >
> >
> > Ara, do you not see value in a Ruby VM, or is just that speed is not, in
> > itself, a justification for a VM?
>
> i'm saying that gcc kills any vm both on speed and portability, including
> windows, and has decades of hard work put in.

I wouldn't be so sure of that. I work with Java for several years now
and we do have performance critical parts in our application. First, I
doubt that a C++ version will show *significant* performance
improvements if at all (because there's a lot IO going on but also
because a JVM is neither slow nor dumb). Second, with a JVM you get a
lot of smartness with regard to memory handling etc., runtime
optimization and instrumentation. Current JVMs' instrumentation
interfaces give you a lot of options in analyzing runtime behavior of
your application.

<OT>Personally I prefer Java over C++ because you get a lot things for
free (thread handling, memory management) that you have to use non
standard libs in C++ for or have to do it on your own. Plus, you still
get a relatively clean OO programming model. From what I hear from my
colleagues the portability of C++ apps is an issue in practice as soon
as you do not limit yourself to Unixes.</OT>

> > (The speed-related advantage to a VM is that it does not require one to know
> > C, etc.,  or have a compiler for all target platforms.  Maybe not as fast as
> > tight compiled C, but also not as much trouble.  It's a trade.)
>
> hmmm.  i think sun's experience with the java vm shows otherwise - remember
> when you couldn't even 'stop' threads!  i think making a fast, protable, vm is
> a lions job.  however, i'd be quite happy to be wrong, it just seems
> un-likely.  consider how long has parrot been 'almost', for example...

Again, if you look at and use modern JVM's from Sun you'll see that
it's quite fast and stable. I know it's a lion's job but Sun and
others have invested serious amount of work into this.  If you want to
get an impression of this I can dig up some links on JVM internals
that will show you how smart and complex those beasts have become.
I'd certainly love to see Ruby use a VM with that much power. (And
yes, I don't have performance issues with Ruby, just to state it. :-))

Kind regards

robert

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