Well that depends on where they measure.
I asked MSI this morning where the temp sensor on the board for the systemtemp is located and got this back:
Generally, system temp sensor is near the IO chip.
For MS-6590, it\'s located on RT3, a thermistor (10Kohm/1%, 0603).
Only I can\'t find it.....help me looking........ :D
If we know where it is, we probably know why it\'s higher :D