The latest driver version is 22.214.171.12404 from 3/11/2016. Give a try and let me know the results.
This processor supports memories of DDR4 2133MHz at 1.25V and DDR3 1600MHz at 1.35V.
Well, it is a rare issue; the Intel® Pentium® Processor G4500 supports the resolution below with high speed video cables.
HDMI 1.4: 4096x2304@24Hz
DP 1.2: 4096x2304@60Hz
More details about maximum resolutions:
It is better to down clock the speed of the RAM to DDR4 2133MHz at 1.20V (1.25). The memory controller is inside the processor and memory might be over clocking the processor and graphics will be affected too.
I have reduced the RAM-Speed as suggested by you. The maximum possible resolution still is 1920x1080.
Do you have any other idea what we can do ?
You said this is a rare issue. In this case I think Intel will not develop the driver much in this direction ?
Would it help us to build in a graphic card ?
Thanks and best regards.
Intel is always improving Intel® HD Graphics performance. Now, a dedicated graphics card might provide with better graphics experience.