My friend have GTX 660 , it can handle 4xIR in any game for sure
If you still have frame drops at 2x then your problem shall not be gpu bottleneck . i7 4770k @ 4.5GHz is pretty damn powerful CPU for Dolphin, it's unbelievable to have any frame drops with that beefy specs
Try Direct3D backend and Vbeam speed hack (right-click the game - properties) or overclock emulated wii
https://forums.dolphin-emu.org/Thread-list-of-games-playable
also while you're at it , you should try this custom Dolphin build for speed
https://forums.dolphin-emu.org/Thread-unofficial-ishiiruka-dolphin-custom-version
If you still have frame drops at 2x then your problem shall not be gpu bottleneck . i7 4770k @ 4.5GHz is pretty damn powerful CPU for Dolphin, it's unbelievable to have any frame drops with that beefy specs
Try Direct3D backend and Vbeam speed hack (right-click the game - properties) or overclock emulated wii
https://forums.dolphin-emu.org/Thread-list-of-games-playable
also while you're at it , you should try this custom Dolphin build for speed
https://forums.dolphin-emu.org/Thread-unofficial-ishiiruka-dolphin-custom-version
Laptop: (Show Spoiler)
Mini PC :: (Show Spoiler)
