ADLINK NuPRO-E330 - Manual (Page 60)

46 BIOS Setup
A20M
A20M# asserted low forces bit 20 of the physical address to be
zero for all on-chip cache or external memory accesses. Leg-
acy operating systems and APs may need A20M enabled.
Intel® C-STATE Tech
C-states are processor power states within the S0 system state
that provide for various levels of power savings.
Intel® SpeedStep™ Tech
This option allows you to enable or disable Intel® SpeedStep
Technology.