I just replaced my Galaxy S5 with an S8. (The S5's screen rotation function had stopped working; it would no longer connect to other devices through USB; and recent Google updates were eating up my battery.) The S8 is advertising as having 4GB RAM. I know that doesn't translate into 4GB actual usable memory, but two different apps report 3371MB of physical RAM. Can anyone on FF explain?
The rest of the ram is probably there just reserved for the OS.
Eta: I see JoeP got the answer first.
(I dont know anything about android memory management but sometimes there's blocks of memory that are made invisible to running programs so that no matter what the system has a block of Ram it doesnt have to share with anyone else, which makes it a bit more secure as well as always available for system things.)