Total Cpu peak - 12 Ghz
Cpu average - 9 to 10 Ghz
What kind of scale is this? You cannot add clock frequencies and claim that means anything. A 10 GHz CPU would vaporize itself the moment you power it up and I'm not too sure if 3 GHz is even in the possible range for the "G5" line (It's PPC970, G5 is just the name Apple sells them under!). The Rev is meant to be an affordable system, i.e. NO PPC970 QUADCORE. PPC970s are expensive and have features your console won't ever need (note to Microsoft: out of order execution is none of them). Four of them are even more expensive. At 3 GHz they'd be f###ing hot, a G5 consumes huge amounts of power already, 3GHz would be a huge increase in power usage. Four of them would need a new powerplant. Don't come with the XBox excuse ("but Microsoft has 3GHz G5s too!"), the X360 does NOT use PPC970s, it uses a chip apparently named PPE that's a severely stripped-down (so much that it has a huge performance impact) version of the PPC970 and meant for embedded devices (such as consoles). The PPE is also the multipurpose core of the Cell.
BTW, there s no "DVD 6GB Dual Layer", DVD Dual Layer is 9GB. The X360 was confirmed to use DVD-9 (the dual layer DVDs), no HD format to be found.