Today, the OS has an increasingly important role and the applications are less-and-less kingdoms of their own that do as they please. Also, with the complexity of games and power of HW increasing, low level programming is used less and less, except for some very critical routines if at all. Hence the limits of OSes (and their SDKs) are a much larger factor than hardware, with a very few notable exceptions (like OpenGL (ES) version, floating point support).