Does the memory controller have the concept of “empty” memory? My understanding is whether memory is in use or not is handled entirely at the operating system layer, not the memory controller, so the memory controller would have to refresh every cell regardless.
What golden settings do you have to accomplish 1.5W screen-on idle? You should share it on this thread where people are going to great lengths to get their laptops down to 4W: [TRACKING] Linux battery life tuning . My laptop is closer to the 6W range at idle with the screen at 33% and AMD’s color-shift power-saving thing at level 2 (amdgpu.abmlevel).