Hi at all, it is a very long time that i don't post anything; but this time i need help for an annoying issue.
I've installed ubuntu 12.04 on my MSI laptop (using an i3 with 4 gb of RAM); but I've very bad performances.
Particularly it takes a lot of time to start from the login screen (about 1 min) and also the performances of the OS are not so good.
Moreover when i try to move windows it is not so smooth. I've thought it was be due to video driver but launching glxinfo | grep rendering i get "yes".

I've used since yesterday ubuntu 11.10 and it was simple perfect and fast for my laptop, the 12.04 is a disaster. What could be?

It is unbelievable that an O.S. is unable to be correctly ran on a dual-core machine with 4 gb of RAM.

p.s.
I use gnome-shell since it is a faster; use unity is quite impossible.