A:Answer I felt I was misled by the in-store promotional display. This could...and should...have been a LOT clearer.
My AN515-53-55G9 came with 1-stick of DDR4-2400 RAM, even though the store display strongly implied DDR4-2666 (and NOT just that it "supports" DDR4-2666), and the store employee could not confirm either way after spending quite some time trying to find-out.
Memory Module Brand/Model as received was:
per CPUz = SK Hynix SO-DIMM 8GB, DDR4-2400, CL17-17-17
Module Label = sk Hynix 8GB 1Rx8 PC4-2400T-SA1-11
I replaced it with these modules that have been running fine for almost 6 months.
Crucial 32GB (2 x 16GB) DDR4 2666MHz DRAM (Notebook Memory) CL19 1.2V DR SODIMM (260-pin) CT2K16G4SFD8266
