I don't understand their complaint about native quad core versus dual dual dies. In practice, the performance penalty isn't that great, and the yields are twice

I don't understand their complaint about native quad core versus dual dual dies. In practice, the performance penalty isn't that great, and the yields are twice as good. For a given sized chip, assuming evenly distributed faults, a die twice as big is four times as likely to have an error. Higher yields mean cheaper and faster (frequency is limited to the portion of a chip which can handle the lowest frequency). In fact, AMD agrees, because they're planning to use dual dies for their 8 and 12 core chips coming in 2009/10. Sure, native quad is elegant, but the end users don't have to touch the design!