An extremely important leak just arrived on our doorstep and (for the first time I think) the leak is provided by Extremetech.com which noticed a very important piece of evidence posted on SA forums. The leak more or less confirms that Excavator cores and the Carrizo APUs will be on the 28nm Process but as always I would recommend that pinch of salt. More interestingly however it also hints that part of the production will shift back to Global Foundries and away from TSMC.

'Excavator Cores' will be on 28nm with 'Carrizo APU' - Production Shift to Global Foundries

There has been some serious speculation whether AMD would shift to 20nm for the Carrizo APU and now it seems to have finally been answered. It appears that AMD will not be shifting to 20nm design and instead stick with a 28nm design. Also part of the production (and I don't know how big that part is) will shift back to Global Foundries.

The screenshot above is the Linkedin profile of a lead engineer. Now you might notice that the standard bulk silicon process that GloFo uses is mentioned (GF28A) and the fact that it shows Kaveri being built on 28SHP silicon process adds authenticity.And wait thats not all. Apparently, an engineer has also been spotted working on the following port technologies:

Porting 28nm TSMC to 28m Glofo.

Porting 28nm Glofo to 20nm Glofo.

Very very interesting. So if this leak is correct then AMD is working on porting existing 28nm TSMC design to Glofo 28nm design. Now a couple of things could fall into this category. The most obvious choice would be Hawaii. Since we know part of the Excavator production of the Carrizo APU will take place in Glofo it only makes sense that the 28nm Hawaii GCN cores are made in the same fab design. And exactly is AMD doing with a 28nm-to-20nm port research. Are they going to pull a Maxwell with Hawaii ? or is it for the ARM sector which will naturally benefit immensely from a die shrink. The answers to that are pure speculation and I will end the article here.