Kubuntu+GeForсe550+3 monitors, how to make friends?

Question

linux

Drivers 310.14, Kubuntu 12.04.
There are 3 outputs on the video card (vga, dvi, dmi). Monitors connected to any two of the outputs both in TwinView and with different X screens work without problems at the same time. In any of the options, the nvidia-settings utility sets the disabled state on monitor 3. I tried to register 3 monitors, 3 devices and 3 screens in xorg.conf with my hands - nothing has changed.
Is it possible to make all 3 monitors work at the same time in such a configuration, or one card will not pull 3 monitors?

update: further googling showed that the vidyuha 3 monitors most likely does not hold, so the question is transformed into how to make friends 2 monitors connected to the gtx550 and one more connected to the integrated card (intel).
All monitors are visible to the system, but the one connected to the built-in card only works in 1 console, and in 7 only those connected to the gtx550 work.

Answer 1

The GeForce 550 only supports two monitors. Proof (page 10) . If you need a third monitor, you need to put the second same video card in SLI.

Answer 2

To connect multiple monitors with different drivers, you can simply configure the X server with two sets of Device, Screen and Monitor sections. This is a very old but still relevant topic.

Answer 3

With closed drivers from nVidia it will not work. You want the X server to have both devices enabled at the same time, but binary extensions and different versions of libGL won't allow that. With open google towards Xinerama.
ubuntuforums.org/showthread.php?p=9562215#post9562215
wiki.archlinux.org/index.php/Multihead