SOLVED: 4K (3840x2160) resolution for Radeon HD 66xx (Turks) in Windows I've got these items, connected by a single HDMI cable: Radeon HD 6670 "Turks" w/ Catalyst 13.4 (GPUZ details) Seiki Digital SE39UY04 39" 4K UHDTV (MONINFO technical details from EDID) Running under Linux (Ubuntu 13.04 64, proprietary Catalyst 13.4), everything automatically comes up perfectly in 3840x2160. (XOrg log) It looks amazing. (screenshot) Under Windows 7 Ultimate 64, the card will only output 1080p (1920x1080). :bang: AMD support claims that "4K Resolution in Windows is only supported in the Radeon HD 7xxx series and later" and that "Custom monitor resolutions are only offered with the FireGL line of cards". Item's I've tried that did not work: Attempting to install ATI 'Hydravision' Monitor Tests Forum Custom Resolution Utility - Ran w/o change after reboot Morris Murphy's ATi Custom Resolution Tool - Couldn't retrieve resolutions, didn't work. Catalyst 13.10 beta drivers Editing DALNonStandardModesBCD1 registry value per this hardforum.com thread Generating a custom monitor .INF file with EnTech Monitor Asset Manager Help greatly appreciated. The card can definitely handle it, as the Linux behavior shows.