I have an HP Envy 700 desktop computer using integrated graphics in Core i7-4770 through an onboard DVI port. The video driver version is 10.18.10.3960 (latest), OS is Windows 8,1 Pro.
The problem appears when connected to the DVI input of my 21:9 ultrawide LG 29MA73V display. I am using the supplied dual-link DVI cable, and Windows does not offer me to choose the native 2560x1080 resolution, only 1920x1080. Furthermore, when I try to make a custom video mode for this resolution, Intel driver says "The custom resolution exceeds the maximum bandwidth capacity" and declines to accept it.
When I connect to the HDMI input of the same display using DVI-HDMI cable, resolution 2560x1080 appears in the list of supported resolution and everything works okay. Both times I am using the same DVI output on the mainboard of my PC.
I attach two reports by Intel driver - one for DVI connection, when 2560x1080 is not present, and one for HDMI connection, when resolution 2560x1080 is present and works perfectly. I noticed that EDIDs from these two different ports of the display are different, HDMI one is bigger, but both of them seem to contain information on the supported 2560x1080 mode.