how can i know wha's the agp bandwidth of my card

there is a lot of card that work at 6gb/s and more but
i'm questionning my self why on the web site of asus ( it a exemple) they
say the agp bandwidth go to
AGP 8X Technology a7v8x-wl

AGP8X (AGP 3.0) is the next generation VGA interface specification that
enables enhanced graphics performance with high bandwidth speeds up to
2.12GB/s and twice as fast as AGP4X.

to get the best of any game a should then choose a motherboard that goes
highier than 2.12gb/s... i'm i ok with that
thought .