We did not validate the GTX 960 as a GPU upgrade option for the Alienware X51 R1. However, some users have confirmed success with non-validated GPU upgrades. I found this thread from the Alienware Arena forum which may be helpful.
Alienware-Rodrigo Dell | Alienware Technical Support #IWork4Dell Opening your case does not void your warranty! Check out Alienware Artificial Intelligence I can't always reply to PM's, if you need extra assistance visit: