Here I attached the issue with using nvidia gpu for xorg rendering.
Please check this video.
Compare to GUI rendering with intel cpu, there are significant delay, rendering issues when gpu is used for graphics.
I switched to gpu graphics by entering below command
$ sudo nvidia-xconfig --prime
I only assume that when gpu is used, it doesn’t really do anything about VGA and only kicks in when 3D graphics required.
I even tried to switch between NVIDIA Performance Mode and NVIDIA On-Demand mode in nvidia-settings but no difference.