Qualcomm's Cortex-A53 based chipsets sip power and it seems that there's a new one in the works. Dubbed Snapdragon 450, it apparently comes from good stock - documentation suggests it is related to the Snapdragon 625. The 625 was a 14nm chipset, and it performed impressively as far as battery life was concerned. Current Snapdragon 4xx chips are built on the older 28nm process (yes, even the latest 430 and 435), which place a limit on their power efficiency (they still did quite okay, though). The GPU will be clocked at 600MHz - perhaps a downclocked version of the Adreno 506 found...
Source: http://www.gsmarena.com/snapdragon_450_in_the_works_apparently_related_to_the_s625-news-25714.php
