User`s manual
68 CMX34GS cpuModule BDM-610000082 Rev A
Performance States (P-states)
The AMD G-Series processor on the CMX34GS supports various operational performance states (P-states) that
are characterized by a combination of the processor’s core frequency and voltage. For each processor type, P0 is
the highest-power and highest-performance P-state of the processor. Each ascending P-state number represents
a lower-power, lower-performance P-state.
The BIOS setup includes options to set whether the processor operates using higher or lower performance
P-States. The default setting is an automatic mode where P-states are entered and exited dynamically based on
internal processor core thermal limits and power-monitoring approximations.
The number of P-states varies based on the cpuModule’s processor. Each processor’s P-states and their
corresponding frequencies are shown in the table below:
AT vs. ATX Power Supplies
Both AT and ATX power supplies may be used with the CMX34GS cpuModule, however AT power supplies do
not provide any standby power to the cpuModule. When an AT power supply is used to power the system, low
power modes that require a standby power to wake the system will not be fully supported.
ATX power supplies do provide a standby power, thus allowing the system to utilize all low power modes
supported by the hardware. When an ATX supply is used to power the cpuModule, lower power modes can be
achieved. During these low power modes, the standby power from the ATX power supply provides power to a
small circuit on the CPU, which is used to watch for a system wake event.
ATX Power Supply Signals
The PCIe/104 Type 2 Bus connectors (CN1 & CN2) provide two ATX style signals., +5V Standby and PSON#. The
+5V Standby rail is used to power certain parts of the cpuModule when the main power supply is turned off, i.e.
during Suspend-to-RAM (S3), Hibernate (S4), or Soft-Off (S5) power modes. The PSON# signal is an active low
open-drain output that signals the power supply to turn on. Use of these signals allows the power consumption
to drop to below 1W during standby modes, and still enable any of the wake events.
Reducing Power Consumption
In addition to the CPU’s low power modes, power consumption can further be reduced by making some
modifications to the BIOS setup. When the following features are disabled in the BIOS, the CPU’s power
consumption will decrease:
•
Ethernet
•
USB Ports
•
SATA Controller
•
Serial Ports
•
Multi-Color LED
Table 45 CPU Core Frequencies per P-state
Part Number Cores Core
Frequency
P0 P1 P2 P3
CMX34GSD1000 Two 1000 MHz 1333 MHz
1
1. In the P0 P-State, only one core of the dual core processor will see the CPU’s boost frequency of 1333 MHz. The
other will see 1 GHz.
1000 MHz 800 MHz 615 MHz
CMX34GSS615 One 615 MHz 615 MHz — — —