@USMAAN A14 chip has a 11.8billion transistors & die size of 5nm as compared to A12z which has roughly 10billion transistors with size of 7nm. Hence more no. of transistors&smaller transistor size(i.e 5nm) makes A14 way more faster than A12z. No. of cores & GPU wont matter SoC. Dont count NO. of cores&GPU on chip for considering speed & efficiency. & lastly increasing transistor count & decreasing chip size will make it more efficient which will require lesser power as compared to 15w as mentioned. so inshort never consider power,no. of cores.no. of GPU for speed. your knowledge is wrong @USMAAN.