I have found older versions of Dolphin still play games acceptably and get much better performance. I have a amd R9 m395 and quad core intel i5, and dolphin 4-5 cannot play games at all. I get 80fps and sound skipping. If I use Dolphin 3.5, I can play the games at 4x native resolution with AA.
That being said, I am willing to help you debug this issue.
That being said, I am willing to help you debug this issue.