270X is faster in everything http://www.anandtech.com/bench/product/1043?vs=1130 If you know its in good condition then get 270X.
http://www.anandtech.com/bench/product/1043?vs=1132 Ahh, life isn't looking so bad these days :bigsmile: If figure its better to go for Mantle because I'll have an i7 before Dx12 ever becomes mainstream.
Always R9 270X 256bit better than Gtx 750ti 128bit. But choose wisely from: Gigabyte,Msi,Sapphire.Carefully with other manufacturers. Good luck.