As you get the following error:
Error: alternatives are not set up properly
You may try to set the alternatives yourself.
When I switch to Intel I see:
update-alternatives: using /usr/lib/nvidia-331-prime/ld.so.conf to provide /etc/ld.so.conf.d/x86_64-linux-gnu_GL.conf (x86_64-linux-gnu_gl_conf) in manual mode
update-alternatives: using /usr/lib/nvidia-331-prime/alt_ld.so.conf to provide /etc/ld.so.conf.d/i386-linux-gnu_GL.conf (i386-linux-gnu_gl_conf) in manual mode
When I switch to NVIDIA I see:
update-alternatives: using /usr/lib/nvidia-331/ld.so.conf to provide /etc/ld.so.conf.d/x86_64-linux-gnu_GL.conf (x86_64-linux-gnu_gl_conf) in manual mode
update-alternatives: using /usr/lib/nvidia-331/alt_ld.so.conf to provide /etc/ld.so.conf.d/i386-linux-gnu_GL.conf (i386-linux-gnu_gl_conf) in manual mode
So you could try this to switch to Intel:
sudo update-alternatives --set x86_64-linux-gnu_gl_conf /usr/lib/nvidia-331-prime/ld.so.conf
sudo update-alternatives --set i386-linux-gnu_gl_conf /usr/lib/nvidia-331-prime/alt_ld.so.conf
Obviously you should replace 331 by your own version.
Now you could try a few things to trigger the switch:
Log out and log in again
to restart the X server as you normally would do
Reboot your whole PC
for the same purpose of the above
Execute sudo prime-select nvidia
as your alternatives are now set for Intel, I hope this will also fix any other settings so that everything is as it should be again (obviously you should still restart the X server)
I hope that I've interpreted the error right.
Also, you could use prime-select query
to check which card is currently selected, and fix the alternatives for that card (for example NVIDIA) as you may somehow have set alternatives for the other card (for example Intel), but the tool is still thinking that you're using the other card (for example NVIDIA), thus giving an error saying that the alternatives are not set up properly.
Best Answer
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:
On the other hand, you can try
bumblebee/optirun
as described in Correct nvidia+intel graphics setup in 14.04Then you can start
ue4
withoptirun
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: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