I have an Intel i7-4771 CPU @ 3.50Ghz with 16Gb ram, An ASUS H87-PRO motherboard, a GeForce GTX 650 Ti BOOST and 700 wattage of power. How much would wattage would I need if I were to replace the 650 with a 970? Is a 700 Watt power supply enough or would I face issues with that?