I am now on discrete in the BIOS and using newer nvidia drivers (304.43) from https://launchpad.net/~ubuntu-x-swat...ive/x-updates/ that support K1000M. External monitor works perfectly as far as I'm concerned.
I also get 60fps on glxspheres, but that doesn't matter to me. Performance seems to be great in any app I've tried. Haven't tried 3D games.
$ apt-cache policy nvidia-current
*** 304.43-0ubuntu1~precise~xup1 0
500 http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/ precise/main amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/restricted amd64 Packages
500 http://security.ubuntu.com/ubuntu/ precise-security/restricted amd64 Packages
500 http://us.archive.ubuntu.com/ubuntu/ precise/restricted amd64 Packages
Polygons in scene: 62464
Visual ID of window: 0x27
Context is Direct
OpenGL Renderer: Quadro K1000M/PCIe/SSE2
58.311433 frames/sec - 65.075559 Mpixels/sec