The Iris 5200 is only available in Crystal Well CPUs. All Crystal Wells are quad core and either have a BGA socket or a R-series SKU.I love my 2013 rMBP 13"... But it would've loved to have an Iris 5200 in there. Is there a particular technical reason why apple didn't put that graphics system in there?
They used to be named after places. Mostly in California if I recall correctly. But that was many years ago in the Penryn and Nehalem days (Wolfdale, Yorkfield, Harpertown, etc).They have an entire team of well-payed professionals on it 24/7
Your second explanation is more like it.Apple could have included it, but chose not too, I can only surmise that they did it to further differentiate between the 13" and 15" model.
Another logical explanation is that it could be too hot for such a small enclosure, the small fans may not have been strong enough to evacuate the heat sufficiently