I have a Macbook pro retina with 650m GPU with 1 GB GDDR5, on windows:
1280x720 high settings - 40-50fps.
1080p low settings 30-40 fps.
1080p medium settings i have around 20-30 fps.
Although the 650m from my computer have equivalent speeds to 660m notebooks, I don´t think he need try so...