Your suggestion about a "pre-Optimus" Geforce, and all mobile Radeons holds force. An Optimus, however, is hardly any better than an Intel video chip any more, and in fact, gives up a large part of what the definition of GPU includes to become a back end only, with the Intel chip handling all of the normal front end chores. There is no way to shut the Intel out, and since Intel could give no better than a Rat's rear end of concern about anyone else's video, the switching is haphazard, undependable, unreliable, etc.
Laptops are terrible game platforms, have almost uniformly awful keyboards, and I have stopped owning any ages ago, when my days on the road came to an end. Desktops can be made small & comparatively compact, and have much better economics (cost way less to own per year), and are longer lived in every way. Those are the proper gaming PCs.
I agree but not everyone can afford (or wants to have) 2 computers and some people need laptops. A laptop with a GTX 860M should easily run this game, but he needs to get the latest driver from the manufacturer or a pre-optimus driver release (or manually tell it to run the 860M for hardline...otherwise the computer will tell him the 860 device was removed when the driver determines (for whatever reason) that the IGP should be used to play.
An Optimus vs a great many high intensity games is a carnival sideshow of frustration. The owner has to find every one of several settings in the Geforce Control Panel and set them all to force the GPU to wake up, and do it every time he buys a next new game, and today's typical laptop owners simply do not usually have the level of enthusiasm for technical matters to follow through. Instant gratification has ruined that generation of would-be game players.
Oops, sorry, I got up on my apple box and preached without covering everything. If a person has to have a laptop for travel, make it a cheap and basic one to save money for the compact size stationary gaming system, keep it until it quits, and the total cost will be less than replacing laptops every three years, by more than enough to support the separate gaming box.
