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The graphics controller integrated on the i7-3840QM is Intel® HD Graphics 4000, this graphics controller does not support 4k screen resolutions, the highest resolution you would get through Display Port is 2560*1600, this information is available here:
Additionally, when using HDMI on Intel® HD Graphics 4000, the maximum resolution is 1920x1080 at 60 Hz .
Below you will find information about graphics controller supporting 4k:
Wow Allan, I am so terribly surprised at how WRONG you are on so many levels.
First of all, I can PNP my monitor at 95Hz@1920x1080, 55Hz@2560x1440, and 25Hz@3840x2160. So you are horribly off base.
SECONDLY!!!!!! That guide lists the HD 4000 as being able to support 60Hz@2560x1600 using DisplayPort, but I am only getting 55Hz at a lower resolution, so SOMETHING IS OFF.
How about you actually address my issue rather than showing how little you understand about the problem by simply redirecting me to a reference guide.
This is actually really insulting. I provided more than enough information to at least produce a healthy guess at what may be the issue, but instead you tell me that I am off of my rocker.
Allan is correct that the Ivybridge QM Processors graphics will only support up to 1920x1080 at 60 Hz via HDMI. The max HDMI pixel clock on Intel Core i7-3840QM is 225Hz and it is the gating spec on maximum resolution (Xx/Hz/bpp). On DP and eDP, the Intel Core i7-3840QM pixel clock is 360Hz which enables a max resolution on DP/eDP of 2880x1800 @ 60/24 Hz, 3840x2160 @ 30/24 Hz, and 4096x2160 @ 30/24 Hz.
On the QM processors you can run 4K at 30Hz via DP/eDp only, HDMI maximum is 1920x1080 60Hz. Additionally your Clevo system is an Hybrid Graphics system as you point out, with an NVidia GTX680m GPU. However, I do not know what the supported resolutions of the GTX680m are. Because it is an Hybrid Graphics system, it is a bit more difficult to determine what is supported and when on your system. Have you contacted Clevo by any chance to see if they have a more detailed specification on what is supported ?
Clarification, this guide is for Haswell and Broadwell based graphics, not Ivybridge. Quick Reference Guide for Intel® Core™ Processor Graphics | Intel® Developer Zone