How to enable 2560x1440 over HDMI on MSI gt780

Question

Has anyone succeeded in doing this?  the gt780 has HDMI 1.4 which should easily handle this resolution.  I bought a new monitor the samsung s27a850.  This  monitor does not have an HDMI port but does have DVI so i just got an adapter and it works fine... except
Under windows it will not allow me to select anything higher then 1920x1080p.  I can use the nvidia driver to create a custom resolution of 2560x1440 and then it works!  Looks awesome!  Until I reboot.  At which point the monitor will not work so I get stuck at load in screen.  I assume this is because the monitor is trying to represent the 2560 resolution but the nvidia driver is not yet loaded.  Anyways its just blackness.
Clearly the HDMI can output this resolution because it works fine when enabled however it appears I need a windows solution so that it can load on boot.  But it wont allow it.  The highest it is allowing via windows is 1920x1080.
Does anyone have a solution for this?

Answer 1

I've done this already, but it was a bit tricky:
1. Make sure you have a HDMI 1.3 cable or better (these are the most common these days), since that's needed for the higher bandwidth.
2. You need to remove the 2560x1440@60Hz custom resolution from the nVidia control panel if you still have that.
3. Add a custom resolution of 2560x1440@35Hz (yes, it must be 35Hz) on the nVidia control panel for your big monitor.
4. Select the resolution and it will work, even across power events like sleep or shutdown.
I found this solution elsewhere, but I can't find that page anymore. So I can't give the proper credits here, sorry.
Personal opinion: It looks like a software only problem. The hardware can handle 2560x1440@60Hz prefectly, but the video card driver breaks down if it needs to initialize that mode again. I guess it will be solved as those higher display resolutions become widespread. Actually, I do better with two 1920x1200@60Hz displays than with a single big one, since handling the windows is easier and a window on a single such display does not load the machine that much. It is also more economic power consumption wise. You can always turn off one of the monitors if not needed and two such monitors often draw less power than the single big one. (Yes, I measured that. Two two monitors have LED backlighting, however...) If you use your machine for work, then I would consider just selling that single big monitor and using two full HD ones instead.