Processor Adaptive Frequency Control via Utilization Data

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Solution Overview

Problem

Existing frequency control mechanisms in processors, such as ACPI-based OS mechanisms, suffer from latency and coarse granularity, leading to inefficient power usage and performance degradation, especially under varying load conditions.

Innovation Solution

Adaptive frequency control is implemented in processor hardware, allowing for real-time adjustment of operating frequency based on processor utilization, using a power control unit to dynamically calculate and update the core clock frequency, thereby reducing idle time and maintaining performance with minimal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If frequency control is implemented using OS mechanism (ACPI), then power consumption is reduced, but latency increases and control granularity becomes coarse

Engineering Contradiction:

Improvepower consumptionVSAvoidlatency

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

A hardware-based frequency control unit is introduced as an intermediary between the processor and the OS, enabling direct frequency adjustment without OS intervention. This mediator handles frequency control in real-time, eliminating the latency inherent in OS-based ACPI mechanisms while maintaining power-saving benefits.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The software-based OS frequency control mechanism is replaced with a hardware-based frequency control unit. This substitution transitions from a mechanical/software system with inherent latency to a hardware system capable of real-time, fine-grained frequency adjustment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If frequency is reduced to save power, then power consumption decreases, but system performance degrades

Engineering Contradiction:

Improvepower consumptionVSAvoidsystem performance

Core Design Contradiction:

Loss of energyVSProductivity

Solution Approach 1:

The frequency control system dynamically adjusts processor frequency based on real-time utilization metrics rather than applying fixed frequency reductions. This dynamic adaptation ensures frequency is reduced only when performance impact is acceptable, maintaining an optimal balance between power savings and system performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system continuously monitors processor utilization and provides feedback to the frequency control unit. This feedback loop enables the system to adjust frequency in response to actual workload conditions, preventing performance degradation by maintaining frequency at levels appropriate for current utilization.

Inventive Principle:

Principle #23Feedback

3Loss of energy

If frequency control is applied unconditionally, then power consumption is reduced, but performance degradation occurs even when utilization is high

Engineering Contradiction:

Improvepower consumptionVSAvoidperformance consistency

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system changes the control parameter from unconditional frequency reduction to utilization-based frequency adjustment. By using utilization percentage as the controlling parameter, the system adapts frequency settings to actual workload conditions, ensuring performance consistency while maintaining power efficiency.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8527796B2Providing adaptive frequency control for a processor using utilization information

Publication Date: 2013.09.03 INTEL CORP

AI summary

In one embodiment, the present invention includes a method for receiving utilization data from thread units of one or more processor cores, determining an operating frequency for a core clock signal based on the utilization data, a target utilization value, and an operating mode of the processor, and generating the core clock signal based on the determined operating frequency. Other embodiments are described and claimed.