Rails app slower on a new Dell with Ubuntu than on an old Mac

Hello people, I have a problem but im not sure if is a problem at all.

I’ve been working in a client project using a macbook pro for two years now.

The project is a rails 2.1.2 app that we are upgrading, it has a lot of tests unit/functional/integration/cucumber

The complete test suite runs slower on a new Dell manchine that on the old Mac. Is that normal?

The specs for the mac are:

2008 macbook pro, lion 10.7.2

8gb ram, 2.53Ghz Core2Duo, 250hd

The specs for the dell are:

New Dell xps 15 (new model that came out this year)

8gb ram, IntelCore™ i7-3632QM, 720hd

It has Ubuntu 12.04 64bit.

I have installed ruby ree with rvm in both laptops

they have the same gems versions managed with bundler

The mac the tests time:

unit

real 9m23.025s

user 3m42.044s

sys 1m40.441s

cucumber

real 13m3.981s

user 8m46.322s

sys 1m24.287s

The dell the tests time:

unit

real 35m4.003s

user 2m52.155s

sys 0m58.388s

cucumber

real 28m54.349s

user 6m32.773s

sys 0m44.751s

Dell times are slow, is there something im missing? is this normal?

How are you compiling it? What are the packages you used to compile
it? What version of Ubuntu?

To compile ruby? rvm does that see pastie http://pastie.org/5342877

Im using ubuntu 12.04