So I'm not well versed in the amount of memory certain functions should take up, but what I have noticed is that the S6 is supposed to have 3G ram right?

Well on my S5 I would have around 1k-1.2k ram unused on average when I would check. The S5 had 2gb of ram and had around conservatively 1000mb free from my experience. So if the S6 has an entire GB more, why am I constantly at ~800 ram free. What is that extra ~1.2k being taking up by the system that's so significant in difference from the S5?

If this has already been answered then apologies but I've been looking around for a while and I haven't come across an explanation yet