Yet the Ultra is distinct for several reasons. First and foremost, Nvidia says the Ultra packs a new revision of G80 silicon that allows for higher clock speeds in a similar form factor and power envelope. In fact, Nvidia says the 8800 Ultra has slightly lower peak power consumption than the GTX, despite having a core clock of 612MHz, a stream processor clock of 1.5GHz, and a memory clock of 1080MHz (effectively 2160MHz since it uses GDDR3 memory). That's up from a 575MHz core, 1.35GHz SPs, and 900MHz memory in the 8800 GTX.