Performance issue, very bad FPS and FPS drops

When I play the game on the lowest settings, it is playable for 2 minutes then the FPS begin to drop and the game gets slower and slower. On normal settings, the game gets slow when I start driving. Menus are getting laggy too. I don't think it's my computer, as it runs NFS MW 2012, FIFA 14 and other recent games smoothly on medium/high settings. I bought the game on Origin 2 days ago and it has always been that slow. Hoping EA will release a patch quickly.