I addressed gaming on the Surface in another thread. I am a hardcore gamer. As such, I know full well that the Surface is not a gaming machine. To even think so is asinine. Will it play games, sure. Will it play them at an acceptable frame rate? No way. At least not the games I play.
I can assure you that the Surface 4 will not be able to game any better if it keeps the same GPU regardless of what processor you put in it.
So, all you 'gamers' out there trying to make a case for Surface gaming, why do it? You know that it will never run Titanfall as well or even close to your gaming rigs regardless of what Microsoft says. If your plan was to buy a Surface 3 because you wanted it to play games, then, my friends, you are buying the wrong laptop. Take your hard earned money and buy an ASUS or Alienware (Dell now?) or any other gaming laptop. But then you will be lugging around a big, heavy powerhouse that only gets 1.5-2 hours battery time.
But, I suspect you gamers already know this. There is some fun in pushing/tweaking devices to their limit. I recall modifying autoexec.bat to load HIMEM.sys. Been there, done that.