graphics - How to use NVidia Gpu simultaneously with intel HD

My laptop has an high-end NVidia Geforce GTX 860m graphics card and the intel integrated graphics (Intel HD 4600, pretty weak)

So in my case, i have to work in ue4 (very heavy on the graphics card), while from time to time switching to the browser to watch tutorials and find answers to questions.

So is there any way to use the NVidia card for heavy tasks, while at the same time using the intel graphics for browser? Because currently videos stutter extremely, and even web forms are very hard to fill out (a lot of lag while typing)
If anybody could have a solution for this problem, i would thank him very much.

Also, my problem is not the one described here:How to use Intel HD Graphics for regular desktop usage, while just using my NVIDIA GPU for DNN training
because i do not want to switch between GPU's, but run them simultaneously.

Based on your query in http://ubuntuforums.org/showthread.php?t=2291771 and the answers there, what you are asking for is not possible.

From the forum:

From my understanding of Nvidia Optimus technology I do not think it
is possible. The purpose of Optimus is automatic switching between a
more powerful GPU for high intensity graphic tasks with likewise high
battery drain and a less powerful GPU for low intensity graphic tasks
with the benefit of less battery drain.

In Linux we have yet to get an Nvidia driver that will do automatic
switching.

I am guessing that the problems you are having with video play back
are nothing to do with which GPU is being used but in connection with
the CPU being under intensive use and needing to task switch. The
Nvidia GPU should handle video playback easily. If it is not then it
could be a case of too much going on at the same time.

On the other hand, you can try bumblebee/optirun as described in Correct nvidia+intel graphics setup in 14.04

Then you can start ue4 with optirun prefix, thus using the Nvidia card for it and use Intel for other processes like the browser. Open a terminal by pressing Ctrl+Alt+T and enter:

(optirun  &)

The (parenthesis) and & will detach the process from the terminal. This will allow you to work on the terminal after launching the program. There are other ways of completely detaching the program from the terminal.

Also see How does bumblebee optirun actually work?.

I don't have an Nvidia card, so I have not tried it.

Hope this helps