Well, cube a quadcore chip on all sides except the bottom. Use the center for you interconnects... then all you would need is some copper wrapped around the sides of the chip to contact the chips that are, you guessed it, on the sides. Of course, it would need to be effective at transfering the heat towards the top like a conventional chip design. Wish I had a drawing... but I am sure you all slightly understand where I am going with this. It would still get hotter then hell and need to have superior cooling. Maybe start with Intels fabrication process... a step up from 45nm, is it 30? I forget. That would surely help keep it cool especially with that new transistor gating technology. It would work fine. Just be a complex process that would cost way too much damn money to mass produce. So... 4x4x4x4x4 @ 2.6Gzh = 20 cores @ 2.6Ghz? Woo! and NO, that wouldnt be FIFTY-TWO GIGAHERTZ. Jesus, some people are hopeless. Anyway, nothing OBVIOUSLY is threaded like that. Well, I remember being able to set the amount of threads in a video conversion program... I suppose programs like that would have a field day. Of course, the entire subsystem would need to be revamped as well. Its all just bunk talk now anyway. Nice to imagine!