Fresh install of 12.04
01:05.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI RS880 [Radeon HD 4200]
'Additional Drivers' shows ATI/AMD proprietary FGLRX graphics driver, and ATI/AMD proprietary FGLRX graphics driver (post-release updates) as not installed. ATI/AMD proprietary FGLRX graphics driver says it installs successfully when I try. The post-release updates say they fail (and when they fail the graphics driver no longer shows as installed either).
I did sudo apt-get install fglrx, which said it was already installed and sudo apt-get install fglrx-updates which installed something. I then restarted.
AMD control center is available and I can use it to get a dual monitor desktop working (which I cannot do with system settings -> displays).
Graphics performance is bad:
If I click and drag on the desktop the selection rectangle cannot keep up with the cursor and Xorg briefly uses a lot of cpu (observed in top).
Visiting eg youtube.com makes the chrome tab unresponsive and makes chrome use a lot of cpu
Scrolling in chrome is laggy.
I have seen compiz using a lot of cpu in top, but it also sometimes sits at around 4% (still at the top of the list but ok I guess?) it's at 45% right now.
I was running 12.04 in 2D desktop mode prior to this but was still having problems with eg scrolling in chrome, I was hoping a reinstall would help, but apparently not. What's the best way to resolve this? Get a new graphics card? try Mint instead? or is there a way to get this graphics card working happily with 12.04?