At an official AMD event prior to the launch of their Phenom II CPUs (the 45nm K10 quad-core Deneb), a team of overclockers got a Deneb to boot at 6.28GHz using liquid nitrogen cooling. It could run Crysis at ~6.1GHz and complete 3DMark at ~6.0GHz. According to AMD, the CPUs at these events aren't cherry-picked either.
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My take:
While retail Phenom II chips will likely not reach such high speeds on air cooling, AMD claims that the initial retail chips can hit 4.0GHz on air. Chips will be sold as high as 3.0GHz commercially, but with the vastly improved overclocking potential and some revisions over the Deneb lifecycle, I estimate retail chips will eventually be sold at 3.4GHz.
Unofficial pre-release benchmarks, based on engineering sample Denebs and the already-released server versions, Opterons based on the Shanghai core, a 3.0GHz Deneb can match a 2.83GHz Penryn (45nm Core 2 Duo) in most applications and beat a 3.0GHz Penryn in some. DDR2-supporting (Socket AM2+) chips will go on sale in early January at around $250 for the 3.0GHz unlocked version, and DDR3 (Socket AM3) chips in February. Tri-core, L3-cache-less and Dual-core versions will go on sale later this year.
