On Aug 19, 9:31  
> I'm evaluating Ruby for use in a variety of systems that are planned by
> default to be Java.
>
> I've started down a path of doing various performance tests to see what
> kind of impact will occur by using Ruby and in my first test the numbers
> are very poor - so poor that I have to question if I'm doing something
> wrong.
>
> I've tried it on both Linux and Mac OSX and get similar performance
> numbers on each - differences being hardware, but the ratio between the
> results about the same.
>
> Please take a look at my blog post on my test results and view the
> source code and let me know if I'm doing something completely wrong with
> the Ruby code or execution - or if these are accurate numbers.
>
> http://benjchristensen.com/2009/08/18/initial-impressions-on-ruby-per...
>
> NOTE: This is not an attempt to start a flame war. This is a legitimate
> effort to take a good look at Ruby and let the numbers speak for
> themselves in making decisions for what types of applications I can
> choose to use Ruby for without sacrificing the performance of a mature
> platform such as Java.
>
> Thank you.
>
> Ben
> --
> Posted viahttp://www.ruby-forum.com/.

Well.... without having put a ton of thought into this... yes, Ruby
(*especially* 1.8 MRI) is slow. No one's going to argue that the Ruby
interpreter is one of the quicker kids around. If performance is the
#1 priority of whatever you'll be developing, Ruby doesn't fit your
needs, and no one will tell you it does. That's what Java (for the
most part) and C are still hanging around for.

What sort of software is in needed of being developed here?

Ask yourself: is it critical that my code always performs as fast as
possible? Or is the greater concern speed of development and project
maintainability?

Also as to the benchmark... can you post your /tmp/file_test.txt?
Posting some benchmarky code isn't very useful if no one can replicate
your results. Reading the whole file into memory may be faster than
reading it line-by-line (but obviously the wrong thing to do if the
file's enormous, which.... 8 secs to read??? i'd better be moved to
tears by the size it.) And not entirely sure what it is you're trying
to benchmark here? Vagggguuee benchmarks are fairly useless, as the
code your timing is never going to be anywhere close to the actual
code you'll write. Are you trying to just compare file reading times?
Benchmark that, and only that. Is there something specific string
manipulation-wise you want to measure? Then... measure that. Until
your code starts getting at least halfway specific, just doing a line-
by-line Java-Ruby conversion doesn't tell anything, as the code that
happens is neither the most "elegant" *nor* fastest Ruby can do.