Why do people say that Ruby is slow? [closed]

Answer 1

The answer is simple: people say ruby is slow because it is slow based on measured comparisons to other languages. Bear in mind, though, "slow" is relative. Often, ruby and other "slow" languages are plenty fast enough.

Answer 2

Obviously, talking about speed Ruby loses. Even though benchmark tests suggest that Ruby is not so much slower than PHP. But in return, you are getting easy-to-maintain DRY code, the best out of all frameworks in various languages.

For a small project, you wont feel any slowness (I mean until like <50K users) given that no complex calculations are used in the code, just the mainstream stuff.

For a bigger project, paying for resources pays off and is cheaper than developer wages. In addition, writing code on RoR turns out to be much faster than any other.

In 2014 this magnitude of speed difference you're talking about is for most websites insignificant.

Answer 3

Writing code is slow. Reading code is slow. Finding and fixing bugs is slow. Adding features and enhancements is slow. Anything that improves on the previous is a win. Very rarely is execution performance an issue.

Answer 4

Joel on Software - Ruby Performance Revisited quite well explains it. Might be outdated though...

I would recommend to just stick with it as you're used to Ruby on Rails,
if you ever meet a performance issue you might reconsider to use a different language and framework.

In that case I would really suggest C# with ASP.NET MVC 2, works very well for CRUD apps.

Answer 5

First of all, slower with respect to what? C? Python? Let's get some numbers at the Computer Language Benchmarks Game:

• Ruby 1.9 vs. Python3 within the same order of magnitude
• Ruby 1.9 vs. PHP within the same order of magnitude
• Ruby 1.9 vs. Java 6 server up to two orders of magnitude slower!
• Ruby 1.9 vs. C (gcc) up to two orders of magnitude slower!
• ...

Why is Ruby considered slow?

Depends on whom you ask. You could be told that:

• Ruby is an interpreted language and interpreted languages will tend to be slower than compiled ones
• Ruby uses garbage collection (though C#, which also uses garbage collection, comes out two orders of magnitude ahead of Ruby, Python, PHP etc. in the more algorithmic, less memory-allocation-intensive benchmarks above)
• Ruby method calls are slow (although, because of duck typing, they are arguably faster than in strongly typed interpreted languages)
• Ruby (with the exception of JRuby) does not support true multithreading
• etc.

But, then again, slow with respect to what? Ruby 1.9 is about as fast as Python and PHP (within a 3x performance factor) when compared to C (which can be up to 300x faster), so the above (with the exception of threading considerations, should your application heavily depend on this aspect) are largely academic.

What are your options as a Ruby programmer if you want to deal with this "slowness"?

Write for scalability and throw more hardware at it (e.g. memory)

Which version of Ruby would best suit an application like Stack Overflow where speed is critical and traffic is intense?

Well, REE (combined with Passenger) would be a very good candidate.

Answer 6

Ruby performs well for developer productivity. Ruby by nature forces test driven development because of the lack of types. Ruby performs well when used as a high level wrapper for C libraries. Ruby also performs well during long running processes when it is JIT-compiled to machine code via JVM or Rbx VM. Ruby does not perform well when it is required to crunch numbers in a short time with pure ruby code.