The memory controller manages its voltage independently of the cores and may lower the voltage in case of lower load.
M3A has an bios option that allows disabling one of the DCS's for power saving if not used. Think that's what they meant in the source the write for the article used here.
But it sounds like the NB has todaly independant power management which is wrong.

Trying "Auto Clock" here again. Does the board monitor show the currently testing "ref HT". Here it's always at 200MHz.

Did not try that STC thing. Think i must write an app handeling that interupt the STC generates if temps exceed.