You would see a performance difference yes, but you're in a position where the i7 4790k, though it may be pushing 5 years, it's still a relevant processor by today's standards. If I were in your position, i'd wait for Intel to counter. It may be 1-2 years, but the fact that you have to spend $500 on a hyper-threaded 8 core chip is ridiculous. I say give Intel a chance to respond/counter to Ryzen 3rd gen because you'll likely get more cores/threads at a higher frequency for the money when it's time. If you must upgrade now, go Ryzen 3rd gen. The i7 9700k is the future i5. Games like Battlefield V peg i5 hex core processors at 100% load already.