turns out i was over complicating things as usual had to turn physx setting to low and game runs fine, also note that this setting can only be accessed from the main menu itself before you start the game.
i also had settings in my nvidia panel so i now allow the game to use more ram and default use my graphics card which also helps.
although i still would like to know if there is limitations, would like it to use all my gpu for vr emulation