The NVIDIA GTX 470 and GTX 480 video cards are already fast by all accounts with very impressive performance. When you take those already fast video cards and then overclock them, you squeeze even more performance out of the cards.
Zotac has announced what it claims to be the world's fastest air-cooled GTX 400 series video cards. The cards are the GTX 470 AMP Edition and the GTX 480 AMP Edition. The cards use a new cooling system to deal with the extra heat generated by overclocking made from a pure copper base and heat pipes with aluminum fins.
The GTX 480 AMP edition has a core clock of 756MHz, a processor clock of 1512MHz, and a memory clock of 3800MHz. The GTX 470 video card has a core clock of 656MHz, processor clock of 1312MHz, and a memory clock of 3402MHz.