actually i mean is, if you add a graphics card than you'll be able game at high resolution. & at high resolution or say added details level your processor will be stretched. but at low resolution the processor isn't stretched fully.
recommended i.e. full utilization only when you add a card. ok, take an example.
take a car with a top speed of say 150mph. you speed it up & it reaches 120-130mph but recommended or max official speed is 150mph. & its really hard to reach that speed. add NOS (in case of PC, its the graphics boost). the car will easily race to 150mph & will try go even fast but can't go as car's max speed is 150mph. i.e. the NOS is being bottlenecked by the max speed of car. something that you'll observe if you add a mainstream card like HD57** or GT44* or above.
hope my "odd style" of explaining cleared your doubts