Determining memory failure points and their levels of storage density
Determining memory failure points and their levels of storage density
The model Cmk16x4m2b3200c16 refers to a specific memory die with a 4x density configuration. The 'b' indicates it's a B die, which is standard for this series. You're right about the x4 meaning four times higher density than standard, so you're on the right track.
It isn't Samsung, probably Samsung SK Hynix. The 80$ kit is a budget model. The X4 reference in the part number seems unclear—maybe it's not relevant.
Samsung and Hynix versions can be tested with Thaiphoon Burner to check for Samsung B-Die compatibility.