Adaptive GPU Caches: Dynamic Associativity for Tag CAM Power

Solution Overview

Problem

Existing graphics processing units (GPUs) face challenges in optimizing power utilization due to varying cache associativity and utilization patterns, leading to inefficient power usage and increased tag content addressable memory (CAM) power consumption.

Innovation Solution

The method involves monitoring cache hit rates and adjusting cache capacity and associativity levels dynamically based on utilization, transferring data between caches, and maintaining different power levels to optimize power usage, while reducing tag CAM power by reducing associativity during low utilization periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cache associativity is increased to improve cache hit rate, then cache performance is improved, but tag CAM power consumption increases

Engineering Contradiction:

Improvecache hit rateVSAvoidtag CAM power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of cache associativity based on workload characteristics. The system monitors cache performance metrics and automatically adjusts the associativity level (e.g., switching between 8-way and 16-way associative) to match the current workload requirements. This dynamic approach ensures high cache hit rates when needed while reducing tag CAM power consumption during low-utilization periods, directly resolving the contradiction between reliability and energy usage.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the associativity parameter of the cache based on detected workload patterns. By analyzing cache access patterns and performance metrics, the system adjusts the associativity parameter to optimize the trade-off between hit rate and power consumption. This parameter adjustment allows the cache to adapt to varying workload demands without maintaining high associativity constantly, thereby reducing unnecessary tag CAM power consumption.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If cache capacity is increased to improve data storage, then cache effectiveness is improved, but power consumption increases

Engineering Contradiction:

Improvecache effectivenessVSAvoidcache power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of cache capacity based on workload characteristics. The system monitors cache performance metrics and automatically adjusts the capacity level (e.g., switching between different cache size configurations) to match the current workload requirements. This dynamic approach ensures high cache effectiveness when needed while reducing cache power consumption during low-utilization periods, directly resolving the contradiction between reliability and energy usage.

Inventive Principle:

Principle #15Dynamics

3Use of energy by moving object

If cache associativity is reduced to decrease tag CAM power consumption, then power usage is reduced, but cache hit rate may decrease

Engineering Contradiction:

Improvepower usageVSAvoidcache hit rate

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The system employs feedback mechanisms to monitor cache performance continuously. By tracking cache hit rates and workload characteristics, the system receives feedback on the effectiveness of current associativity settings. This feedback loop enables the system to adjust associativity dynamically, ensuring that power consumption is reduced only when it does not negatively impact cache hit rate below acceptable thresholds, thus resolving the contradiction between power usage and reliability.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent implements dynamic adjustment of cache associativity based on workload characteristics. The system monitors cache performance metrics and automatically adjusts the associativity level (e.g., switching between 8-way and 16-way associative) to match the current workload requirements. This dynamic approach ensures high cache hit rates when needed while reducing tag CAM power consumption during low-utilization periods, directly resolving the contradiction between reliability and energy usage.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12462331B2Adaptive caches for power optimization of graphics processing

Publication Date: 2025.11.04 QUALCOMM INC

AI summary

Aspects presented herein relate to methods and devices for graphics processing including an apparatus, e.g., a graphics processing unit (GPU). The apparatus may monitor a first hit rate for a first cache at a first capacity level. The apparatus may also adjust a capacity of the first cache from the first capacity level to a second capacity level. Further, the apparatus may calculate a second hit rate for the first cache at the second capacity level. The apparatus may also readjust or maintain the capacity of the first cache based on a difference between the first hit rate for the first cache at a first capacity level and the second hit rate for the first cache at the second capacity level. The apparatus may also output an indication of the readjusted capacity of the first cache or the maintained capacity of the first cache.