A:Answer As mentioned in the previous Answer, you will need 850W power supply just to be on the safe side. you can still run 3090 with i7 8700K, but your FPS will be a little bit lower compared to a newer Intel i7. There's a great video on youtube where they benchmark test i7 8700K, 9700K, and 10700K. I'm currently running i7 10700 non-K version with the 3090. Works great. To give an idea CPU Mark results for 10700 is 17491 and the 8700K is 13899.
If possible the 3080 or AMD 6800XT would be a better choice/deal. Originally wanted the 3080, since I was unable to obtain one, but got very lucky to get the 3090 FE on BestBuy. Happy with my choice, since I was about to buy the 2080ti, glad I waited. Shout Out to Best Buy, At least they're trying to make it fair as much as possible. Trust me I know, been trying since day one, compared to NewEgg, you have a better chance with BestBuy. Good luck and game on.
