I am not a mobile hardware expert, but I consider Brian Klug of AnandTech one, and here’s what he has to say about the way Qualcomm names its processors:
Yup, even Brian is confused about what exactly qualifies a Qualcomm chip to be called a Snapdragon 600 or a Snapdragon S4 Pro. And don’t get me started on the elusive difference between S4 Plus and Snapdragon 400…
The latest case of confused identity is the SoC inside the new Nexus 7. Officially, Qualcomm calls it a Snapdragon S4 Pro, just like the SoC inside the Nexus 4. Except the APQ8064–1AA features four Krait 300 CPU cores, instead of the four Krait 200 cores inside the Nexus 4. Moreover, there are 2GB of DDR3L-1600MHz SDRAM in there, instead of the LPDDR2 RAM found on the Nexus 4.
So, for all intents and purposes, Brian thinks, the APQ8064–1AA SoC inside the Nexus 7 is a Snapdragon 600 underclocked at 1.5GHz. Officially, S600 chips are clocked above 1.7GHz, which might explain why Qualcomm decided to call the APQ8064–1AA an S4 Pro.
The discrepancy between the S4 Pro inside the Nexus 4 and the S4 Pro inside the Nexus 7 (2013) explains why the new 7-inch tablet does really well in a series of benchmarks ran by AnandTech:
One other major improvement hardware-wise is the presence of improved eMMC flash storage modules. As a result, the 2013 Nexus 7 clearly outperforms the 2012 Nexus 7 in storage benchmarks, and we expect to see the difference to feel in real life as well.
What does all this technobabble mean for the average user? It means that the new Nexus 7 should perform vastly better than the old Nexus 7 or the Nexus 4, even if, at first sight, the differences between them aren’t that big. And that’s all that really matters at the end of the day.