so MB is a sabertooth x79 12 gig DDR3 i7 3820 extreme CPU. 3 HDD's 1 SDD. sealed water cooled by corsair. NVIDIA Geforce 680 graphics, 1 dvd rewrite-able drive 1 media card reader 1 WiFi card all powered by a corsair HX 750. (given specs so ya can work out power consumption) can I purchase a Nvidia Geforce RTX 2060 without having to buy a Corsair HX 1000 or would i need to buy the PSU first.