It shouldn't make a ton of difference if any of the four screens are receiving input or not, Dolphin will have a lot more to process regardless, and you'll see how demanding 4-player mode is anyway. You just "plug in" 4 emulated Wiimotes (or GCPads) into Dolphin and take it for a spin.
With an i7-4770K though, it's really only a question of if you need to OC, and if so, how high? Except for a few instances, there's really not a lot your CPU can't run at fullspeed when it comes to Dolphin.
With an i7-4770K though, it's really only a question of if you need to OC, and if so, how high? Except for a few instances, there's really not a lot your CPU can't run at fullspeed when it comes to Dolphin.