Comment 7 for bug 1482273

Nevermind, this bug is still present in 3.13.0-63-generic. I was wrong about the bios setting in post #5. The only reliable way to boot a current kernel with working smp is to first boot linux-image-3.13.0-57-generic, then reboot into the latest kernel. Kernels linux-image-3.13.0-62-generic and linux-image-3.13.0-63-generic do run stable once booted, the others I mentioned earlier are unstable if booted. On a related note, I see Dell has stopped offering the Ubuntu Edition of this laptop.