Virtual Operating Point for Processor Power Management

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Solution Overview

Problem

Current computing systems face inefficiencies in managing processor discrete operating points, leading to suboptimal power consumption and performance, as the combination of operational frequency and voltage often does not match desired power states, resulting in increased design and testing costs and reduced performance.

Innovation Solution

Implementing a method to manage multiple discrete operating points by identifying a stable virtual operating point through power-performance state transitions, using a power model to set operational voltage and frequency, and toggling between discrete states to maintain a desired power target, thereby optimizing power utilization and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If more discrete P-states are added to provide finer grain combinations of operational frequency and voltage, then power management flexibility is improved, but design and test costs increase

Engineering Contradiction:
Improvepower management flexibilityVSAvoiddesign and test costs
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of operating points by introducing a virtual operating point that is not fixed to discrete P-states. Instead of adding more discrete states, the system dynamically adjusts operational frequency and voltage to achieve a desired virtual operating point, providing flexibility without increasing device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a virtual operating point as an intermediary between discrete P-states. This virtual point acts as a mediator that allows the system to target specific power-performance combinations without being constrained by available discrete states, resolving the contradiction between flexibility and complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If a close-matching discrete P-state is chosen to match computed operational frequency and voltage, then power consumption is reduced, but performance is reduced below computed power limit

Engineering Contradiction:
Improvepower consumptionVSAvoidperformance
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies dynamics by transitioning from static discrete P-state selection to dynamic operation around a virtual operating point. The system can continuously adjust frequency and voltage to maintain optimal performance at the desired power level, rather than being locked into fixed discrete states that may underdeliver performance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters by targeting a virtual operating point that specifies desired frequency and voltage combinations. By dynamically adjusting these parameters around the virtual point, the system achieves both the desired power consumption and corresponding performance, resolving the trade-off between power reduction and performance maintenance

Inventive Principle:
Principle #35Parameter changes

3Productivity

If operational frequency and voltage are increased to meet power target, then performance is improved, but power consumption increases beyond limits

Engineering Contradiction:
ImproveperformanceVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements feedback control by continuously monitoring power consumption and adjusting operational frequency and voltage to maintain operation at the virtual operating point. This feedback mechanism ensures performance is maximized while staying within power limits, as the system dynamically corrects deviations from the target power-consumption balance

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2583151B1Managing multiple operating points for stable virtual frequencies
Publication Date: 2018.08.22 ADVANCED MICRO DEVICES INC
  • EP2583151B1 patent drawingFigure 1
  • EP2583151B1 patent drawingFigure 2
  • EP2583151B1 patent drawingFigure 3

AI summary

A system and method for managing multiple discrete operating points to create a stable virtual operating point. One or more functional blocks within a processor produces data corresponding to an activity level associated with the respective functional block. A power manager determines a power consumption value based on the data once every given sample interval. In addition, the power manager determines a signed accumulated difference over time between a thermal design power (TDP) and the power consumption value. The power manager selects a next power-performance state (P-state) based on comparisons of the signed accumulated difference and given thresholds. Transitioning between P-states in this manner while the workload does not significantly change causes the processor to operate at a virtual operating point between supported discrete operating points.