I see a lot of benchmarks between PHP, Python, Ruby, etc all over the Internet. Ruby has gotten a lot of flak for being super slow, which leads to developers refusing to use it for web development for “performance reasons”. But does the performance of the interpreter really matter for web applications? Isn’t the bottleneck located in the database 99% of the time anyway? So why is everyone freaking out?
Note: I realize that in some edge cases, such as certain mathematical/scientific web applications, performance matters a lot, but I’m not talking about those; I’m talking about your average social networks, Stack Overflows, etc.
Does performance matter? Eventually, sure.
But your website will have to get so large that you’re into the millions of hits per month range before it will even be an issue for you outside of traditional optimization (eg proper indexing in your database).
I don’t think the Ruby distaste is so much to do with performance (although there have been issues with this). It’s more that it’s unproven, has a reputation for instability and forced a very rigid framework on you (yes I know you can use Ruby without Rails, etc). I’m not a Ruby fan for the same reason I’m not a fan of the heavyweight PHP frameworks like CakePHP or Symfony: I find these frameworks overly invasive and so heavyweight that you’re not doing PHP anymore. Compare this to lighter weight framewrks like CodeIgniter, which have a much better return on investment (imho).