I want to buy a 27 inch monitor with a resolution of 2560x1440. I will use it for photography, so color management is very important. My current NVidia driver doesn't allow color management in Unity (Ubuntu 11.10). What video card should I buy to allow a color managed display with a resolution of 2560x1440?
I got no answer, so I experimented myself and answer my own question in case others are interested too.
First of all: the Phoronix site has lots of information about the performance of graphic adapters in Linux.
Second: color management in Gnome 3 (or Unity in Ubuntu 11.10) only works if the graphic adapter driver supports xRandR version 1.3 or higher. NVidia drivers don't, so NVidia adapters are not supported bij the Gnome color management tools. There are alternatives (like using dispCalGUI as a startup application), but these have drawbacks. AMD Radeon cards have open source and proprietary drivers that support xRandR 1.3. So I bought a HD 6850 card. These cards support DisplayPort cables. So I could connect my 27 inch monitor easily.
Third: I tried the proprietary driver first because I expected better performance, but all kinds of errors occured. Using ALT+TAB to switch between applications for instance led to weird problems (the Unity menu bar disappeared, and big jpeg's were not displayed by the default Gnome image viewer). So I returned to the default open source driver packed with Ubuntu 11.10. This driver works flawlessly with all kinds of software, and color management is supported.
So, now I am a happy 27 inch screen user. Editing photographs with Corel AfterShot Pro and stitching panorama's with Hugin. Thanks Ubuntu! Thanks all open source developers! And thanks to Gnome.