FAN CONTROL DURING LOW TEMPERATURE OPERATIONS TO REDUCE PLATFORM POWER

• US 20150143147A1
• Filed: 10/21/2014
• Published: 05/21/2015
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Hee-Jun Park, John Wallace
• Original Assignee: Hee-Jun Park
• Inventors: Wallace, John, PARK, Hee-Jun
• Granted Patent: US 9,459,677 B2
• Time in Patent Office: Days
• US Class Current: 713/320
• CPC Class Codes: G06F 1/203 for portable computers, e.g. for laptops
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G06F 1/3234 Power saving characterised by the action undertaken
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

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 CPU temperature enough to decrease CPU 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., CPU 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.

Claims

1-14. -14. (canceled)

15. A method comprisingdetermining a power consumption of a computer system, wherein the power consumption of the computer system comprises at least a sum of power consumption for a cooling fan and power consumption for a device being cooled by the fan;

2) changing a fan speed of the fan in a first direction and determining if the power consumption of the computer system increased or decreased after said changing in the first direction;

3) i) if the power consumption decreased in operation

     2), changing the fan speed again in the first direction;

ii) if the power consumption increased in operation

     2), changing the fan speed in a second direction;

iii) if the power consumption did not change in operation 2, not changing the fan speed;

4) repeating operations

     2) and

     3);

wherein said first direction is either increasing or decreasing the fan speed, said second direction is decreasing the fan speed if the first direction is increasing the fan speed, and the second direction is increasing the fan speed if the first direction is decreasing the fan speed.

16. The method of claim 15, wherein said determining if the power consumption of the computer system increased or decreased comprises determining if the power consumption changed by more than a predetermined amount.

17. The method of claim 15, wherein the first direction is increasing the fan speed and the second direction is decreasing the fan speed.

18. The method of claim 15, wherein the first direction is decreasing the fan speed and the second direction is increasing the fan speed.

19. The method of claim 15, wherein said changing the fan speed occurs at predetermined intervals.

20. An apparatus comprising:

a fan;

a CPU;

a fan controller to control the operation of the fan, wherein the apparatus is to control a speed of the fan by

A) determining a power consumption of a computer system, wherein the power consumption of the computer system comprises at least a sum of power consumption of the fan and power consumption of a device being cooled by the fan;

B) changing a fan speed of the fan in a first direction and determining if the power consumption of the computer system increased or decreased after said changing in the first direction;

C) i) if the power consumption decreased in operation

     2), changing the fan speed again in the first direction;

ii) if the power consumption increased in operation

     2), changing the fan speed in a second direction;

D) repeating operations B) and C);

wherein said first direction is either increasing or decreasing the fan speed, said second direction is decreasing the fan speed if the first direction is increasing the fan speed, and the second direction is increasing the fan speed if the first direction is decreasing the fan speed.

21. The apparatus of claim 20, wherein said determining if the power consumption of the computer system increased or decreased comprises determining if the power consumption changed by more than a predetermined amount.

22. The apparatus of claim 20, wherein the first direction is increasing the fan speed and the second direction is decreasing the fan speed.

23. The apparatus of claim 20, wherein the first direction is decreasing the fan speed and the second direction is increasing the fan speed.

24. The apparatus of claim 20, wherein said changing the fan speed is to occur at predetermined intervals.