Hi! I'm having problems with Far Cry 3 being choppy like a slideshow, I'm talking like 3-5 FPS, when i'm playing the story line the fps is so low that the talking will be over with, but the video still plays.

I have 4 gigs of RAM, an ATI Radeon HD 4200 graphics card, and an AMD Athlon II quad core processor 2.8GHz. I have all of the settings on low.
I've been told that it could possibly be my motherboard causing the problem, but that sounds like an expensive fix/upgrade.