Low FPS all of the sudden

[Hdtv]

I log in today after some like 3 days and i get like 15 fps in SW instead of 100, same goes for northrend really low, i can't figure it out, it's only in wow wotlk warmane

I think i know what it is, but idk how to change it in wotlk, for some reason when i logged in retail it was using onboard graphics, it worked fine after selecting the GPU in options, but wotlk doesn't have that option.