By Nick Farrell
21 November 2008, 11:51 AM

AMD SHOWED OFF its upcoming 45-nanometer 'Deneb' desktop chips for reviewers in Texas on Thursday, and overclocked it to what some observers said was 6.3GHz. The Deneb chips, which are going to be the Phenom II's, were cooled by liquid nitrogen but other hacks said that it hit 4GHz with air cooling and 5GHz with dry ice cooling.

The top Phenom II chip, due out sometime in the first quarter of 2009, will reportedly list as 3.0GHz off the shelf. Intel's top Core i7 processor has been overclocked to 4.5 GHz on air cooling alone and some claim to have taken it to 5.7GHz using liquid nitrogen. AMD said that the Phenom II demos were done on what the chip maker is calling its 'Dragon' platform which is a quad-core Phenom II processor. It also had an ATI Radeon 4800 series discrete graphics and an AMD 790 chipset.

AMD said the extra level of "headroom" towards dramatic overclocking capacities on the Phenom II parts is due to a combination of architectural improvements over the original Phenoms first released late in 2007. A spokesman said it was about high-speed path optimisations, memory pre-fetch, how it does branch predictions and the larger cache. The result has been modest improvements on instruction per clock but much better clock frequency.