GPU with Dynamic Performance Adjustment

• US 20130328890A1
• Filed: 08/27/2012
• Published: 12/12/2013
• Est. Priority Date: 06/07/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Avkarogullari, Gokhan, Law, Patrick Y., Wyrzykowski, Michael J.
• Granted Patent: US 9,250,665 B2
• Time in Patent Office: Days
• US Class Current: 345/501
• CPC Class Codes: G06F 1/206 comprising thermal management
• 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 one embodiment, a system includes a power management controller that controls a duty cycle of a processor to manage power. By frequently powering up and powering down the processor during a period of time, the power consumption of the processor may be controlled while providing the perception that the processor is continuously available. Additionally, in some cases, it may be a better power/performance tradeoff to run the processor at a higher power/performance state if the processor is executing for a significant portion of the execution interval (e.g. the frame time for a GPU). Executing at a higher power/performance state may permit a realization of a greater number of frames per second for a given workload, in an embodiment.

Claims

1. An apparatus comprising:

a graphics processing unit (GPU); and

a power manager controller coupled to the GPU and configured to monitor power consumption in the GPU and to control a power/performance state of the GPU responsive to the power consumption, wherein the power manager controller is configured to determine a utilization of the GPU at a time that the GPU is operating at a lower power/performance state of a plurality of power/performance states, and wherein the power manger controller is configured to cause the GPU to operate at a higher power/performance state during the execution interval responsive to the utilization exceeding a first threshold.

2. The apparatus as recited in claim 1 wherein the power manager controller is configured to detect that the GPU reaches an idle condition during the execution interval, and wherein the GPU is configured to operate the GPU at the higher power/performance state in a next execution interval responsive to the GPU reaching the idle condition at and further responsive to the utilization exceeding a second threshold.

3. The apparatus as recited in claim 1 wherein the power manager controller is configured to detect that the utilization in a next execution interval exceeds a third threshold, and wherein the power manager controller is configured to cause the GPU to operate at the higher power/performance performance state in a second next execution interval responsive to the utilization exceeding the third threshold.

4. The apparatus as recited in claim 3 wherein the third threshold is greater than the first threshold and the second threshold is greater than the third threshold.

5. The apparatus as recited in claim 1 wherein the power manager controller is configured to cause the GPU to operate at the lower power state responsive to a thermal limit being reached in the apparatus.

6. The apparatus as recited in claim 1 wherein the execution interval is a frame time in which a frame for display is processed by the GPU.

7. The apparatus as recited in claim 1 wherein the power manager controller is further configured to monitor transitions in the power/performance state of the GPU and, responsive to detecting one or more patterns in the transitions, the power manager controller is configured to dynamically modify the first threshold.

8. The apparatus as recited in claim 7 wherein the power manager controller is configured to increase the first threshold responsive to a first pattern of the one or more patterns, and to decease the first threshold responsive to a second pattern of the one or more patterns.

9. A method comprising:

operating a graphics processing unit (GPU) at a first power/performance level during a frame time;

detecting that a utilization of the GPU exceeds a first threshold; and

transitioning the GPU to a second power/performance level during the frame time responsive to detecting that the utilization exceeds the first threshold.

10. The method as recited in claim 9 further comprising:

detecting an idling of the GPU during the frame time, wherein the utilization at the idling exceeds a second threshold;

initiating a second frame time on the GPU; and

operating the GPU at the second power/performance level in the second frame time responsive to detecting the idling.

11. The method as recited in claim 10 further comprising:

detecting that the utilization exceeds a third threshold in the second frame time; and

operating the GPU at the second power/performance level during a third frame time responsive to detecting that the utilization exceeds the third threshold.

12. The method as recited in claim 11 wherein the first power/performance level comprises a first operating frequency and the second power/performance level comprises a second operating frequency, and wherein the second operating frequency exceeds the first operating frequency.

13. The method as recited in claim 12 wherein the first power/performance level comprises a first power supply voltage magnitude and the second power/performance level comprises a second power supply voltage magnitude, and wherein the second power supply voltage magnitude exceeds the first power supply voltage magnitude.

14. The method as recited in claim 9 further comprising:

detecting that the utilization exceeds a third threshold in a second frame time; and

operating the GPU at the second power/performance level during a third frame time responsive to detecting that the utilization exceeds the third threshold.

15. An integrated circuit comprising:

a processor; and

a power manager controller configured to operate the processor at one of a plurality of supply voltage magnitudes and a corresponding one of a plurality of operating frequencies, and wherein execution in the processor is divided into a plurality of equal-sized execution intervals, wherein the power manager controller is configured to measure a utilization of the processor, and wherein the power manager controller is configured to determine which one of the plurality of power supply voltage magnitudes and which corresponding one of the plurality of operating frequencies to select for the processor responsive to the utilization, wherein at least one transition between power supply voltage magnitudes and corresponding operating frequencies is performed dynamically during a given execution interval responsive to the utilization.

16. The integrated circuit as recited in claim 15 wherein the power manager controller is configured to operate the processor at a first power supply voltage magnitude and a first operating frequency during a first execution interval, and wherein the power manager controller is configured to dynamically change the first power supply voltage magnitude and the first operating frequency to a second power supply voltage magnitude and a second operating frequency during the first execution interval responsive to the utilization in the exceeding a first threshold.

17. The integrated circuit as recited in claim 16 wherein power manager controller is configured to detect that the processor transitions to idle in the first execution interval and, responsive to the transition to idle occurring and the utilization exceeding a second threshold, the power manager controller is configured to select the second power supply voltage magnitude and the second operating frequency for a second execution interval subsequent to the first execution interval.

18. The integrated circuit as recited in claim 17 wherein the second threshold is greater than the first threshold.

19. The integrated circuit as recited in claim 15 wherein, responsive to operating the processor at the second power supply voltage magnitude and the second operating frequency during a second execution interval and the utilization exceeding a third threshold, the power manager controller is configured to select the second power supply voltage magnitude and the second operating frequency for a third execution interval subsequent to the second execution interval.

20. The integrated circuit as recited in claim 19 wherein the third threshold is greater than the first threshold.

21. The integrated circuit as recited in claim 15 wherein the second power supply voltage magnitude is greater than the first power supply voltage magnitude and the second operating frequency is greater than the first operating frequency.

22. A computer accessible storage medium storing a plurality of instructions which, when executed on a device that includes a processor:

monitor a utilization of the processor during an utilization window;

responsive to the utilization, determining a power/performance state for the processor for a next execution interval during a current execution interval; and

program a power manager hardware to request the power/performance state for the next execution interval.

23. The computer accessible storage medium as recited in claim 22 wherein the plurality of instructions, when executed, dynamically increase a current power/performance state of the processor in the execution interval responsive to detecting the utilization exceeding a first threshold.

24. The computer accessible storage medium as recited in claim 23 wherein the plurality of instructions which monitor include instructions which, when executed, detect that the utilization exceeds a second threshold greater than the first threshold before the processor is idle in the execution interval, and the power/performance for the next execution interval is the increased power/performance state responsive to detecting that the utilization exceeds the second threshold.

25. The computer accessible storage medium as recited in claim 22 wherein the plurality of instructions which monitor include instructions which, when executed, detect that the utilization is less than a first threshold, and wherein the instructions that determine, when executed, determining that the power/performance state for the next execution interval is a decreased power/performance state compared to the current power/performance state.