Still can't run most games smoothly.

I am trying to play Twilight Princess and Brawl, but I get big fps dips into the 15 - 20 range when a lot is on screen or when I load a new portion of the world. I don't quite understand why, because I can run the single-player of Battlefield 4 on ultra with AAx2 and get around 75fps on average. I have to bump it down to medium settings in multi-player though. I followed the settings walkthough that's on this website, to no avail.

Specs:

OS: Windows 8 64-bit

CPU: Intel Core i3 2130 @ 3.40ghz

RAM: 8.00gb Dual-Channel @ 665mhz(not the same brand, default and Patriot)

GPU: NVIDIA GeForce GTX 660 2gb