Performance problem with ATI on Ubuntu

So I had a bit of a performance problem since using Ubuntu. Which I am using for about 2 years now. (I didn't use Linux before that for quite some time so I assume its not just a problem with Ubuntu).

At the end I got an AMD Phenom II X4 and a pretty nice graphics card so that should not have been a problem. And yes: I of course used the proprietary drives from ATI.

The symptoms:

• Firefox was slow. Scrolling was stuttering especially when viewing a complex site and changing the font-size/"zooming" took up to a few seconds.
• Flash was extremely slow and so was Acrobat Reader.
• When dragging windows around the screen the computer became slow and it didn't feel very fluid.
• Many Java based programs also ran very slowly.
• All in all the whole system just felt pretty outdated and underpowered despite the used hardware.

Last week I finally replaced the graphics card since my old one was starting to make noises. I switched to nVidia since I could get hands on a passively cooled one pretty easy.

And I have to say WOW: That 50€-card made a fluid, snappy system out of my box.

So I am not sure what to make of this because I couldn't find that much current stuff about ATI being crap on Linux. But if you are experiencing similar problems you should really try using something else than ATI. Maybe its gonna work for you too.