650 Ti on a mix of mostly low and medium settings (although 'textures' are set to good) and framerates haven't been a problem. Granted, the CPU is at and the memory above recommended, though from what has been stated elsewhere even below-minimum CPUs handle the game well enough.

I can't see any reason for a system check to outright prevent the game from launching unless the hardware was so out of date that it was flat-out incapable of providing the necessary functions, but if your hardware was that out of date you probably wouldn't dream of trying to run any modern game on it anyway. :)