are you saying that the CPU freq is variable ? how ?
Like @tkaiser has already explained.
I personally use default settings. And the situation with 600 / 600Mhz suits me. My HC1 spends most of time at idle and only sometimes big cores jump to 2Ghz for a few moments. Personally, I do not feel the need to set 1.4 / 1.6Ghz.
It's different when I use Kodi as an audio player, so I run it only on three little cores and leave the rest alone. Does it affect temperature and power consumption? I do not know, maybe and maybe not....