DON'T FORGET... GPU is also the important part in CEMU...
i can get 50 fps in mario kart 8 (grand prix mode) with weak i3 CPU (using Nvidia GTX 750Ti)
before i can only get 25-30fps in mario kart 8 (grand prix mode) with my weak i3 CPU + GT740.
after i upgraded my GPU from GT740 to GTX750Ti (with using my weak i3 CPU)
i can get 50 fps in mario kart 8 (grand prix mode)
here is the proof (recorded with Nvidia Shadow Play)
i can get 50 fps in mario kart 8 (grand prix mode) with weak i3 CPU (using Nvidia GTX 750Ti)
before i can only get 25-30fps in mario kart 8 (grand prix mode) with my weak i3 CPU + GT740.
after i upgraded my GPU from GT740 to GTX750Ti (with using my weak i3 CPU)
i can get 50 fps in mario kart 8 (grand prix mode)
here is the proof (recorded with Nvidia Shadow Play)
NSMB WiiU may run ok . Other games will not run at full speed or may be too slow to be playable
Even though it's a quad core CPU , its performance per core (single thread performance) is much worse than Haswell / Skylake CPU
I have A10 6790k @ 5.0GHz , it's only on par with Pentium Haswell G3258 @ 3.2GHz (stock speed) in Dolphin
Since Athlon x4 880k is unlocked CPU , you should overclock it as much as possible
You will need high end CPU like i5 4690k/i7 4790k @ 4.4GHz or i5 6600k/i7 6700k to run MKWii at full speed (grand prix mode)