My current phone is advertised as having 3GB of RAM. Under Settings/Memory Total Memory is listed as 2.8GB.
I recently saw a newer phone with a more modern System-On-a-Chip with 4GB of RAM. Total Memory showed as 3.5GB.
From reading around I believe the difference is down to the memory being set aside for graphics (or perhaps peripheral addressing at a guess, failing that).
If the former, as the screen resolution is the same (1920x1080) and I never had a problem with graphics on the old phone with 200MB set aside, is this something that can be varied, perhaps in a custom ROM, for instance Lineage, or would it be be buried too deep in hardware drivers?