3+ monitors, nvidia + intel graphics

I have seen lots of different posts on this issue, but I cannot figure out what to do. I hope we can collect the available information in one place, so that they can be useful for others.

Is it possible to have multiple (3+) monitors running on two different graphics cards?

I have

• 1x nVidia GeForce GTX 550 with 2 DVI ports and
• 1x Intel integrated graphics, with 2 DVI ports.

I understand that they would be running on different instances of X servers. Is that correct? Could someone point me in the right direction to start?

On Windows it's so simple, there is no additional thing to do other than going in display preferences and activating all 3+ monitors. They can even be laid out alternating one monitor from one graphics card with another monitor from the other card.

Solution 1:

In my experience this just does not effing work in Ubuntu currently. I will say that if you have to edit xorg.conf in a reasonably current version of Ubuntu (anything post-Unity), you're doing it wrong -- XRANDR does much better on its own. It's a shame, because the Intel graphics these days are so good, I don't want the adapter to go to waste, but X doesn't know how to use two different GPUs simultaneously.

This may have something to do with the fact that the Intel adapter doesn't actually show up as "VGA compatible" in lspci when you've got a discrete card connected -- but that's all the sleuthing I managed. You should file a bug report; I keep meaning to get around to it.

Solution 2:

Since 13.04 or kernel 3.8 the intel-driver can handle this! (before, the 3. monitor only shows crap, but was activatable) So using the open-source-nvidia-drivers together with the newest kernel should work. It does for me with the actual daily build of 13.04.