Running an NVIDIA GTX 780 Ti Over Thunderbolt 2
 

A common issue for laptop users is the lack of GPU power. Even the fastest mobile GPUs, in SLI or Crossfire cannot reach the echelons of performance of a higher-end desktop, mainly due to the power consumption and heat generation. Not only that, laptops with high-end mobile GPUs in order to cope with heat generation tend to be far from portable. Sure, they are still easy to carry around compared to a full-size desktop system, but not many are willing to carry one around on a daily basis. In other words, if you want a laptop that's relatively portable, you are left with mediocre GPU performance that usually doesn't satisfy the needs if you happen to be an active gamer.

http://www.anandtech.com/show/7987/r...-thunderbolt-2