Intel Kentsfield will most likely be the first consumer processor with four processor cores and Intel’s Conroe-based Quad-core processor looks to be a bit tubby. Everything is of course relative but at XtremeSystems’ forum the user Freecableguy has noticed that his Kentsfield processor’s packaging is considerably thicker than his equivalent dual-core Conroe processor. He has compared two E6700 processors, dual-core vs, quad-core, and estimated that Intel has increased the number of signaling layers from 8 to 10. With four cores it gets a lot more complicated to lead the signals through the processor and this could be the reason for the increased number of layers.
But since he hasn’t made any deeper analysis of the processor you shouldn’t draw any major conclusions from this. That Kentsfield will be extra tricky to manufacture is not something anyone should be surprised over.
Conroe E6700 ES vs. Kentsfield E6700 ES: Photo by Freecableguy