Mediatek doesn't manufacture its mainstream (careful mainstream for Mediatek's standards) in anything better than 28HPm right now unless I'm missing something. One might say that MTK's next batch of SoCs will be for N manufacturing process, but by that time Pinecone V670 won't be a mainstream SoC in the grander scheme of things anymore either.
In line with the above: http://www.anandtech.com/show/10758/qualcomm-adds-new-snapdragon-socs-include-support-for-8gb-ram
No idea if QCOM is dual sourcing the 625, but if not it's being manufactured on 14LPP Samsung. Besides the point. The real point is that a 28nm process even today is by far not unreasonable for anything mainstream or lower. For the given case unless Xiaomi hasn't announced all its SoC plans yet, it smells more like that they'll use a high end Snapdragon above their V970 which looks like their mainstream offering of the neareast future.
The Note Pro 3 seems to have a better battery life at 28nm than the Note 4 here despite the 20SoC for the latter http://www.anandtech.com/show/11137...port-xiaomi-redmi-note-4-mediatek-helio-x20/4
yups! thats why i have commented about it and my skepticism about helio x30 in my first post here but it was moved to x20 thread