A single X session cannot span two graphics cards. X just doesn't support it. You're waiting on Mir or Wayland for that one. If you manage to get all four moni

A single X session cannot span two graphics cards. X just doesn't support it. You're waiting on Mir or Wayland for that one. If you manage to get all four monitors on one card somehow, X can handle the multiple geometries just fine. Though it will generally do a terrible job of automatically detecting the right resolution. Love Linux, but this bit does disappoint.