Its commonly known that the mobile chip variants are actually just derived from the desktop ASIC's, and this became much more evident when high end desktop graphics chips, which have little care about power utilisation in reality, suddenly started sprouting power management features that would be useful in the mobile space, which have battery longevity concerns to deal with. What eventually gives M18 away is its feature capabilities, which included PS2.b and 3Dc, something hitherto related only to the R4x0 of desktop chips.