Intel CPU Power Delivery Design Guidelines and Specs: Vdroop Explained
 

A very technical article from the guys over at thetechrepository tries to give us a look on vdroop issues for processors on the Intel side of things:

"Allowable tolerances are a necessity in any engineering discipline. Set them too tight and you will find that the combination of component values, manufacturing uncertainties and design margins create a situation in which products never meet validation criteria. Set them too loose and performance may suffer. In either case, the designer(s) must take into account a myriad of variables, some which may be totally transparent to the consumer. [...] Often times consumers have no idea of the stagger amount of time and resource it takes to sufficiently develop and test a design before release. Re-spins and re-works are relatively cheap when still in the development phase; but expenses can become overwhelming when dealing with a release-to-manufacture (RTM) product. What does all of this have to do with power regulation circuits? The short answer, as we shall see, is everything.

http://www.thetechrepository.com/showthread.php?t=126