REGULATING POWER WITHIN A SHARED BUDGET

• US 20110055596A1
• Filed: 09/01/2009
• Published: 03/03/2011
• Est. Priority Date: 09/01/2009
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Wyatt, David
• Granted Patent: US 8,826,048 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Metrics representing a combined measure of power used by a central processing unit (CPU) and power used by a graphics processing unit (GPU) are compared to a shared supply power and/or shared thermal power budget. A state of the CPU and a state of the GPU are regulated by the power management system to maintain the metrics within the shared supply power and/or thermal power budget for the purpose of managing the components to meet platform power supply, and cooling, constraints and design requirements.

Claims

1. An apparatus comprising:

a central processing unit (CPU); and

a graphics processing unit (GPU) communicatively coupled to the CPU;

wherein a first thermal management system compares a metric representing a combined measure of power used by the CPU and power used by the GPU to a shared power budget, wherein a state of the CPU and a state of the GPU are regulated to maintain the metric within the shared power budget.

2. The apparatus of claim 1 wherein the shared power budget comprises a budget selected from the group consisting of:

a shared thermal power budget; and

a shared supply power budget.

3. The apparatus of claim 1 wherein the metric is selected from the group consisting of:

an integral value of the power utilized by the CPU and the power utilized by the GPU over a first period of time;

an instantaneous value of the power utilized by the CPU and the power utilized by the GPU over a first period of time;

a rate of change of the power utilized by the CPU and the power utilized by the GPU over a first period of time;

a moving average of the power utilized by the CPU and the power utilized by the GPU over a first period of time.

4. The apparatus of claim 3 wherein the metric further comprises a prediction of a value for the metric for a second period of time after the first period.

5. The apparatus of claim 1 further comprising:

a first sensor operable for measuring power used by the CPU; and

a second sensor operable for measuring power used by the GPU, wherein the first and second sensors are operable for sending an event signal when a threshold is crossed and wherein, in response to the event signal, a management unit coupled to the first and second sensors is operable for polling the first and second sensors to access data useful for determining the metric.

6. The apparatus of claim 5 further comprising a controller operable for receiving an alert from the management unit, wherein in response to the alert the controller initiates a change to at least one of the state of the CPU and the state of the GPU.

7. The apparatus of claim 1 wherein the state of CPU and the state of the GPU also are regulated using pre-determined profile information for an executing application.

8. The apparatus of claim 1 wherein the state of the CPU and the state of the GPU also are regulated according to preferences selected from the group consisting of:

user preferences;

operating system preferences; and

platform-specific preferences.

9. The apparatus of claim 1 further comprising a cooling fan having an adjustable fan speed, wherein the fan speed is reduced if the metric is less than the shared power budget.

10. The apparatus of claim 1 further comprising a legacy thermal management system, wherein responsibility for managing the CPU and the GPU transitions from the legacy thermal management system to the first thermal management system when the first thermal management system is enabled, and transitions from the first thermal management system to the legacy thermal management system when the first thermal management system is disabled.

11. The apparatus of claim 10 wherein the legacy thermal management system polls the first thermal management system to confirm operability of the first thermal management system.

12. The apparatus of claim 10 wherein the legacy thermal management system specifies the budget to the first thermal power management system in response to an event that affects the budget.

13. The apparatus of claim 12 wherein the legacy thermal management system changes the budget in response to a change in cooling capability selected from the group consisting of:

fan speed;

internal temperature; and

external temperature.

14. A system for managing a central processing unit (CPU) and a graphics processing unit (GPU), the system comprising:

a management unit operable for comparing a metric comprising an integral value of power utilized by the CPU and power utilized by the GPU over a period of time to a budget; and

a controller coupled to the management unit and operable for regulating power used by the CPU and power used by the GPU to maintain the metric within the budget.

15. The system of claim 14 wherein the metric further comprises a prediction of power utilization by the CPU and by the GPU at a point subsequent to the period of time.

16. The system of claim 14 wherein a first sensor is operable to measure power used by the CPU and a second sensor is operable to measure power used by the GPU, wherein the first and second sensors are operable for sending an event signal when a threshold is crossed and wherein, in response to the event signal, the management unit is operable for polling the first and second sensors to access data useful for determining the metric.

17. The system of claim 16 wherein the management unit is further operable for sending an alert to the controller, wherein in response to the alert the controller initiates a change in at least one of a state of the CPU and a state of the GPU.

18. The system of claim 17 wherein the state of the CPU and the state of the GPU also are regulated using pre-determined profile information for an executing application.

19. The system of claim 17 wherein the state of CPU and the state of the GPU also are regulated according to user preferences.

20. The system of claim 14 further comprising a cooling fan having an adjustable fan speed, wherein the fan speed is reduced if the metric is less than the budget.

21. A computer-implemented method of power control, the method comprising:

comparing a metric comprising an integral value of power utilized by a central processing unit (CPU) and power utilized by a graphics processing unit (GPU) over a period of time to a budget; and

regulating a state of the CPU and a state of the GPU to keep the metric within the budget.

22. The method of claim 21 wherein the metric further comprises a prediction of power utilized by the CPU and by the GPU at a measurement point subsequent to the period of time.

23. The system of claim 21 further comprising:

receiving an event signal from at least one of a first sensor operable for measuring power used by the CPU and a second sensor operable for measuring power used by the GPU;

in response to the event signal, polling the first and second sensors to access data useful for determining the integral value; and

sending an alert that initiates a change in at least one of a state of the CPU and a state of the GPU.

24. The method of claim 21 wherein the regulating the state of the CPU and the state of the GPU comprises using information selected from the group consisting of:

pre-determined profile information for an executing application, and user preferences.

25. The method of claim 21 further comprising reducing a speed of a cooling fan if the metric is less than the budget.