What do you mean by slow?
It is interesting, since Ubuntu is like lightning on my Acer and hp machines and OpenSUSE is slow.
Ubuntu 9.04 is already optimized for high speed, so you need to find out which process is hagging the time. If you are getting a 1-2min disparity, then something is timing out. Find out what that is and disable that process.
Have you tried running a
boot analyzer?
Speeding up Ubuntu involves switching services off, and customizing upstart.
http://upstart.ubuntu.com/