Sapphire Radeon R9 4GB vs EVGA GeForce GTX 750 2GB?

I'm doing my first computer build and I wonder which graphics card will give me more fps on computer games (TF2, Counter Strike 2, Minecraft)

The cards that I've been wondering about are the GeForce 750
(http://www.amazon.com/EVGA-GeForce-Dual-Link-Graphics-02G-P4-2758-KR/dp/B00J3ZNB04)

and the R9 270x
(http://www.newegg.com/Product/Product.aspx?Item=N82E16814202049)

The EVGA card has the G-sync technology along with much higher clock speeds, whereas the AMD card has double ram and higher memory bandwidth.

If it matters, I will be getting the Core i5 4670k to go with the gpu

The 270X by far is better than the 750. The equivalent of the NVidia of the 270X is of the 760

The cards are from different classes. The NVidia 750 is like the Radeon 260X. The 270X is the next step up.