I dont believe they used anything "special". They may have used a hybrid Asus board but that certainly wasnt the reason for the massive overclock - and 5ghz may not have been 100% stable, but it is certainly impressive. They used a 3.2ES Prescott to get 5ghz. In fact, one Xtreme Systems member got the same chip to 5.1 I believe. Nobody can ever say for sure what overclock you will get - its the luck of the draw in most cases, and a lot of patience.