Monster Hunter Tri - Need help with config.

[admin89]

AMD Phenom II X6 1055t @ 2.8GHz is a six cores CPU but Dolphin is a dual core application . In single threaded performance , it should be on par with an Intel Core 2 Quad @ 2.8GHz which is too old and slow for latest Dolphin . You should overclock your CPU (3.4GHz or higher)
See Official Dolphin Benchmark (Save 2 x64)
Keep in mind that Zelda WW (in the benchmark) is a light-weight game while MH3 isn't and latest Dolphin is more demanding than older version (Dolphin 3.5 , Dolphin 3.0....)
A GTX 660 should be able to handle 4xIR , no AA , 16x AF any game . You have CPU bottleneck