Should I upgrade my processor to i7-4790k for better perfirmance?

[Shonumi]

That's a lot of cash to drop for a CPU whose primary benefit is a higher overclocking ability. Sure you can push the i7-4790K farther than most i5-4670Ks, but a properly overclocked i5-4670K will run just about anything Dolphin can throw at it. In my honest opinion it's not worth it. You'd do well to wait until Skylake comes out if you want an upgrade that's worth your money. So yeah, keep the i5-4670K since it's a beast for Dolphin (that's not going to change any time soon either). Nothing's broken, don't try to fix anything.