I was successfully running my Dell U2711 display over HDMI (1.4) at 2560x1440 @ 60 Hz resolution with my laptop’s GT220M using the NVIDIA driver from the Ubuntu 12.04 release (295.33). The resolution stopped working when the driver was upgraded to a newer version. With any newer versions than 295.33 the display just goes blank as if it didn’t get signal.
After I identified the problem, I tried installing the latest version (319.17; approximately a month or two ago) directly from the NVIDIA website but the resolution didn’t work. Then I installed the version 295.33 from NVIDIA website and the resolution started working again.
However, as I upgraded Ubuntu to 13.04, I cannot use the version 295.33 anymore because the kernel module fails to compile. Therefore, I’m currently limited to the full HD resolution.
As my laptop only has HDMI and VGA outputs, I have to run the display via HDMI. I got the resolution working originally by writing a custom X.org configuration file where I included all options from the NVIDIA driver readme that seemed to be related to EDID or other resolution checks as the display only advertises full HD resolution over HDMI.
Was there a change in the driver after the version 295.33 that prevents driving displays over HDMI at the 2560x1440@60 Hz resolution? If so, could the change be reverted to enable using higher resolutions over HDMI? This could be enabled e.g. with a configuration option.
Or are there any configuration options that I have missed that are required by newer driver versions to get the resolution working? Please advice if I can modify my X.org configuration somehow to get the resolution to work again.
I can still use the 2560x1440@60 resolution in Windows 7 on the same laptop over HDMI by using a custom resolution that I have created with the NVIDIA configuration utility. See the attached screenshots for driver version and custom resolution configuration.
This issue is similar to the one reported by kosh81 in the post https://devtalk.nvidia.com/default/topic/528241/linux/can-39-t-use-2560x1440-55hz-over-hdmi-under-linux-win7-works-/post/3733827/#3733827