Ultrawide 3440x1440 monitor at 60hz with Mid-2012 Retina MBP

[Xgatt]

My MBP is mid 2012 running El Capitan. I own an XR341CK, which runs at 3440x1440, and the only way I'm able to use it is over HDMI@30hz or Thunderbolt/Mini Displayport @30hz. The moment I try to change the monitor to 60hz(NTSC) in display preferences, it goes blank, disconnects, reconnects while remaining blank, and disconnects again. This loops ad infinitum.

It has Intel HD 4000 and NVidia 650M for graphics, and both of those SHOULD be able to power this resolution at 60Hz according to multiple reports on the internet (although the spec for the laptop itself says max of 2560x1600 online).

So I want to confirm finally: will this laptop ever run 3440x1440 at 60hz? If so, how to get this to work?

Here's what all I've tried:

1. Setting monitor to DP 1.1 through OSD
2. Changing color settings on monitor
3. Disabling overdrive on monitor

Here's what I've not tried:

1. I have read various threads about using a modified kext file with a bigger framebuffer
2. Running some ruby script to force the computer to recognize the monitor as a monitor and not a tv

I would appreciate any input on this.

 

[wegster]

Should work as my 2011MBP dGPU is driving a 34" 3440x1440 w/out issue, from TB(1) -> Displayport or TB->TB, at 60Hz.
Others have reported similarly.
Note I am running Sierra - unsure if that makes any difference here. 'Shouldn't' but can't confirm.

Have you tried using a tool like SwitchResX or another cable?

 

[Xgatt]

I think I will need to try it with another cable or something, as it simply refuses to pass a signal properly. Which cable are you using currently (brand as well would help)?
EDIT: Also, switchresx is unsuccessful in forcing 3440x1440 @ 60hz over thunderbolt to mini-dp.

 

[flimbs]

Did you ever solve this? I have the same problem..