Introduction

The Core i7 4790K – A Silicon Lottery?

You know back in June Intel released Devils Canyon processors, the newly revised Haswell based quad-core processor was to be the hottest 'thang' for overclockers. Unfortunately the results where a bit of a mixed bag, actually the 4770K in a lot of circumstances could be tweaked higher than the 4790K which maxes out mostly in the 4600~4700 MHz range when overclocked. Back in June with Devils Canyon processor release I seriously had a goal to reach the 5 GHz marker with that processor, but whatever I tried, the sample that we retrieved from Intel absolutely maxed out in the 4700~4800 MHz range. So in the back of my head, that always was a bit of an annoyance (with an otherwise lovely product).

A little while ago in our forums somebody mentioned a website based in the 'Silicon Lottery'. The website is selling binned processors, guaranteed to work at a certain clock frequency. Though the idea is nothing new as there are parties out there that purchase a 100 processors and then make a selection, ending up with the best overclockers. So with that 5 GHz marker nagging me, I figured what the hell, Silicon lottery is offering a wide variety of 4790K processors which are binned, what is binning ?
 

Intel Core i7-4790K - Binned Silicon Lottery Devils Canyon processor. 
 

Intel, TSMC, UMC, Global Foundries and others make wafers. With the production there are always slight variations in material quality across the wafer surface, there are local variations in how the lithography, metal vapor deposition, photo resist chemical deposition, etc. are done. If you factor in these variables then the effect can be a yield that significantly differs the final product in terms of worse versus better chips.