Hello, how are you? So to start, What is the make and the model of your power supply?
HA! Forgot to mention that one.
Yeah then you will be fine r9 270 is a great card and will play all the games from ultra to high settings. Don't worry .
Yeah. You may be able to squeeze a 270x, but the 270 is essentially the same card, it's just binned lower. You'll see about 50% increase in gaming performance with the 270 over the 650 Ti, even more if you get a good overclocker