I've been doing a lot of googling these last few hours and I'm not having much luck. Perhaps I don't know exactly what I am looking for.
I just recently installed Ubuntu 12.04LTS x86_64. Looks beautiful!
I have two GTX470's in SLI, and I am finally migrating my desktop over given the hopeful gaming support as of late. My laptop has been enjoying multiple distros of Ubuntu for a couple years now. However, new problems come with unexplored territory, here.
At first, I only had one working monitor of my two. Over on nvidia-xconfig I fixed that, but the only solution that actually worked was twinview. Just recently I read here that twinview is not compatible with SLI. Sweet.
When I try to tell it, oh hey, use a separate XScreen, configure it the way I want it, click save to configuration file, enter my password, then a sudo restart lightdm, it's broken. One screen blacks or whites out (Couldn't tell you the specific conditions for each, I'm dubious at this point,) and I get this huge error dialogue box upon login. Something about incompatible resolutions if I remember right. Though I am sure I set the resolutions for each screen correctly.
Anyway, when I try to enable SLI (sudo nvidia-xconfig --sli=On) despite the fact it hates twinview, unity breaks. The sidebar is there, but only one screen works, the mouse is trapped running along the left edge of it, and the background of the sidebar is a solid blue.
Anyway, this ended up being entirely too verbose, I'm sorry, but could anyone part some wisdom please? It would be appreciated!