skeeter36

Getting another 8GB is the best first move, since memory bandwidth matters a lot in gaming, and an upgrade to Ryzen in the future would also need some dual channel action.

Just pick up a 80 plus GOLD rated of just about any mainstream brand at your 600 watts. Corsairs RM line is good, EVGA has a good line of gold rated PSU's as well.
Its not a place to skimp!! I promise you i learned this lesson the hard way. I feel that if you are trying to build a decent gaming rig in 2019 750 watts and an 80 plus gold rating is about the sweet spot for most builds i would say. Just DO NOT SKIMP here!!

Agreed, I learned this lesson the hard way. For example, A corsair Cx750m wont run a 1080 ti real well if at all. But their RM750X runs it perfectly fine and to its full potential. Same manufacturer and same watt rating but these 2 power supply's are far from equal.

Ok, that makes sense. Nvidia keeps the best chips for themselves and allows board partners to use the lower quality chips.