These ideas get thrown around a lot, and they're pretty proven to work:
1) Upgrade the CPU
2) Overclock the CPU
In all seriousness though, you CPU is very weak for MH3. MH3 is a somewhat demanding game to play, and your system is bottlenecked by the CPU. Turning down the IR aka "the graphics" will not result in a speed up, since that's handled by the GPU. I have the same GPU, so I can safely say that unless you have the IR and AA turned up fairly high (4x IR + various amounts of AA), you won't bottleneck the GPU ordinarily.
Now, you can use the very latest Dolphin revisions. They've been speeding things up recently. If you do, update to the latest Nvidia driver as well; this will let Dolphin do some magic when using OpenGL that may improve overall speed. So upgrade Dolphin, your drivers, and give OpenGL a try.
1) Upgrade the CPU
2) Overclock the CPU
In all seriousness though, you CPU is very weak for MH3. MH3 is a somewhat demanding game to play, and your system is bottlenecked by the CPU. Turning down the IR aka "the graphics" will not result in a speed up, since that's handled by the GPU. I have the same GPU, so I can safely say that unless you have the IR and AA turned up fairly high (4x IR + various amounts of AA), you won't bottleneck the GPU ordinarily.
Now, you can use the very latest Dolphin revisions. They've been speeding things up recently. If you do, update to the latest Nvidia driver as well; this will let Dolphin do some magic when using OpenGL that may improve overall speed. So upgrade Dolphin, your drivers, and give OpenGL a try.