I came across this article: http://www.phoronix.com/scan.php?page=news_item&px=ODAzNg which might be of interest.
As a side note, I have a Radeon 4550 but haven't had time to test its HDMI capabilities yet. -- No sound from Radeon HD 4650 - HDMI Output https://bugs.launchpad.net/bugs/501203 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs