Why is == faster than eql?

Question

I read in the documentation for the String class that eql? is a strict equality operator, without type conversion, and == is a equality operator wh

Answer 1

equal? is reference equality
== is value equality
eql? is value and type equality

The third method, eql? is normally used to test if two objects have the same value as well as the same type. For example:

puts "integer == to float: #{25 == 25.0}"
puts "integer eql? to float: #{25.eql? 25.0}"

gives:

Does integer == to float: true
Does integer eql? to float: false

So I thought since eql? does more checking it would be slower, and for strings it is, at least on my Ruby 1.93. So I figured it must be type dependent and did some tests. When integer and floats are compared eql? is a bit faster. When integers are compared == is much faster, until x2. Wrong theory, back to start.

The next theory: comparing two values of the same type will be faster with one of both proved to be true, in the case they are of the same type == is always faster, eql? is faster when types are different, again until x2.

Don't have the time to compare all types but I'm sure you'll get varying results, although the same kind of comparison always gives similar results. Can somebody prove me wrong?

Here are my results from the test of the OP:

 16.863000   0.000000  16.863000 ( 16.903000) 2 strings with eql?
 14.212000   0.000000  14.212000 ( 14.334600) 2 strings with ==
 13.213000   0.000000  13.213000 ( 13.245600) integer and floating with eql?
 14.103000   0.000000  14.103000 ( 14.200400) integer and floating with ==
 13.229000   0.000000  13.229000 ( 13.410800) 2 same integers with eql?
  9.406000   0.000000   9.406000 (  9.410000) 2 same integers with ==
 19.625000   0.000000  19.625000 ( 19.720800) 2 different integers with eql?
  9.407000   0.000000   9.407000 (  9.405800) 2 different integers with ==
 21.825000   0.000000  21.825000 ( 21.910200) integer with string with eql?
 43.836000   0.031000  43.867000 ( 44.074200) integer with string with ==