I have three systems:
Desktop - FX6100 @ 4.5ghz, AMD 6870 stock, 16gb RAM. This has consistent FPS in any setting
Laptop - Haswell i7m, nVidia 750m SLI, 12gb RAM. This gets consistent FPS.

What I mean by consistent, is that if an area has low FPS, it sticks around 30. In the field, sticks around 50-60 at the top settings I could get consistency.

Then there's my other laptop - Ivy Bridge i7m, nVidia 680m, 12gb RAM. Before I reformatted it in phases 1-4, EA and launch, got consistent fps. Reformatted and now I have this problem. No matter where I am or what's happening, fps always dips in half. I could be getting 90 in the field, drops to 45. 55-60 in town, drops to 25-30. Always half.