Intel taking 6-core route for broken 8-core CPUs
 

One major part of the Xeon presentation is Intel's "cache and core recovery" scheme, which lets the company salvage a usable part from a defective chip by disabling the defective regions and selling the chip with a lower core count or cache amount.

So for instance, if testing and validation finds a defect in a cache slice on a chip, then Intel can disable that slice and sell the chip with lower cache. And likewise with cores, so that you might buy a six-core chip from Intel that was originally produced as an 8-core Xeon but had two defective cores.

http://arstechnica.com/hardware/news...e-recovery.ars

September 2007:

http://www.itwire.com/content/view/14512/1154/

It seems to be a consequence when you put all cores on one die the yields suffer and you have to resort to this method.

Maybe all cores on one die is a stupid move.

stupid move in respect to product yields; intelligent move in respect to performance and power usage ;)