With Ubuntu 14.04 LTS there is improved support for multi-GPU laptops (commonly what's branded as NVIDIA Optimus configurations) where there is a discrete NVIDIA GPU used for high performance workloads to complement the low-power Intel integrated graphics. Ubuntu 14.04 LTS features better support for these Optimus / DRI PRIME configurations on both the open and closed-source graphics drivers. Here's the Ubuntu 14.04 multi-GPU experience along with some OpenGL benchmarks and power consumption numbers between the different configurations.

Now that Ubuntu 14.04 LTS is out the door, I tested it out on a ASUS Zenbook Prime ultrabook with an Ivy Bridge class Intel Core i7 3517U CPU that has HD Graphics 4000 plus a discrete NVIDIA GeForce GT 620M 1GB GPU.