I have VirtualBox running Ubuntu as a guest environment on my Macbook Pro running Leopard OS X 10.5.
I timed the same batch of Ruby on Rails unit tests on both systems. The difference seems to be quite big.
The same suite of Ruby unit tests that take 13.4 seconds in the native OS X, take 82 seconds to run in VirtualBox Ubuntu.
Are other people doing the same kind of development noticing the same differences?
I have 4GB of RAM on the machine, and 512MB base RAM for the guest Ubuntu system (but I think this this number increases dynamically when more RAM is needed).