US 8,145,926 B2Granted

Fan speed control of silicon based devices in low power mode to reduce platform power

AssigneeIntel Corporation

InventorsHee-jun Park, John Wallace

Life of this patent

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Abstract

In general, in one aspect, the disclosure describes running a cooling fan within a computer at low speed while the computer is in low temperature operations (e.g., idle). The operation of the cooling fan may reduce processor (CPU) temperature enough to decrease processor leakage power, offsetting the power consumption of the fan, and possibly resulting in a net system power reduction. The benefit at the platform level increases further when considering the low efficiency of voltage regulation (VR) in this lower power regime, and potentially reductions in other components (e.g., graphics processor). The optimal fan speed is the speed at which the overall system power is reduced the most (e.g., processor power savings is greater than fan power utilized). The optimal temperature may be determined dynamically during operation or may be determined in manufacturing and applied statically during operation.

Claims13

Dependent claims

A method comprising

determining a processor within a system is operating in a low temperature state, wherein while the processor is operating in the low temperature state the processor does not require cooling and a fan within the system used to cool the processor is typically off or operating at a low speed;
determining a preferred speed for the fan to operate at in order to reduce system power when the processor is operating in the low temperature state, wherein the system power includes processor power and fan power, wherein the system power is reduced when the processor power saved by cooling the processor operating in the low temperature state with the fan operating at the preferred speed outweighs the fan power required to operate the fan at the preferred speed, and wherein the determining a preferred speed for the fan includes
measuring the processor power and the fan power when it is initially determined that the processor is operating in a low temperature state prior to any fan speed adjustments,
calculating the system power prior to any fan speed adjustments,
increasing the fan speed,
measuring the processor power and the fan power for the increased fan speed,
calculating the system power for the increased fan speed,
dynamically adjusting the fan speed based on changes to the system power,
measuring the processor power and the fan power for the dynamically adjusted fan speed,
calculating the system power for the dynamically adjusted fan speed, and
selecting the preferred speed when the system power is determined to be substantially at lowest value;
and
running the fan at the preferred speed when the processor is operating in the low temperature state.

10 more elements

A system comprising

a fan;
a processor;
and
a fan controller to control the operation of the fan,
wherein the processor is to
measure the processor power and the fan power when the processor is operating in a low temperature state prior to any fan speed adjustments;
calculate the system power prior to any fan speed adjustments;
instruct the fan controller to increase the fan speed;
measure the processor power and the fan power for the increased fan speed;
calculate the system power for the increased fan speed;
dynamically determine adjustments to the fan speed based on changes to the system power and instruct the fan controller accordingly;
measure the processor power and the fan power for the dynamically adjusted fan speed;
calculate the system power for the dynamically adjusted fan speed;
and
select the preferred speed when the system power is determined to be substantially at lowest value and instruct the fan controller accordingly, and
wherein the fan controller is to
operate the fan at the preferred speed in order to reduce system power when the processor is operating in a low temperature state that does not require cooling, wherein the system power includes processor power and fan power, and wherein the system power is reduced when the processor power saved by cooling the processor operating in the low temperature state with the fan operating at the preferred speed outweighs the fan power required to operate the fan at the preferred speed.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/242,883Filed 30 Sep 2008
Published: US 2010/0083018 A11 Apr 2010
Granted: 27 Mar 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G06F 1/32
Power supply means, e.g. regulation thereof: means for saving power
G06F 1/203
Cooling means: for portable computers, e.g. for laptops
G06F 1/206
Cooling means: comprising thermal management
G06F 1/3206
Power management, i.e. event-based initiation of a power-saving mode: monitoring of events, devices or parameters that trigger a change in power…