It's very unfortunate because it really degrades the Ubuntu experience compared to Windows Vista.
A year ago I bought an AMD/ATI Radeon HD 6670 graphic card because my old Nvidia card was getting too old for Windows 8 and Ubuntu. But when I retried Ubuntu with this newer card, I had a display problem. So I switched back to Windows and waited, telling myself that it would get solved in a future update from the community.
This update finally came between 13.04 and 13.10. The open source drivers could finally make Ubuntu look like Ubuntu instead of a purple screen... But the open source drivers are very, very laggy. So much that I can't handle browsing any web page with Firefox. What feel snappy, surprisingly, are the cursor, the launcher and the dash. So I searched on the Web and found instructions about switching to fglrx and fglrx-updates. Man, you can't know how much this frustrated me. I had to reinstall Ubuntu at least 10 times just because of these graphics. I couldn't see any login screen. So I waited for another update.
Now, one year later I can finally use fglrx and fglrx-updates. However, to my great surprise... it's even laggier than the open source driver!?
I swear it has nothing to do with my graphics card being not fast enough. In Windows Vista, everything is snappy. In fact, my seven years-old laptop with integrated Intel graphics fares better.
What should I do? For now, my only solution seems to stay with Windows...