I recently changed my graphic card with a GeForce GTX 770, it's amazing. I was looking for benchmarks to test it. And I came across these Linux demos and a few games(samples), so I wanted to share them with the GOG community:
Unreal Engine 4
They look amazing.
I recommend Matinee Demo and Shooter Game.

Other benchmarks for Linux:
Unigine

I see no one was interested so far, let's see if we can change that! New Linux UE4 demos are out, and more to come:
Unreal Engine 4 demos