Address Swizzling for 3D Stacked Memory Thermal Management

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Solution Overview

Problem

Thermal issues in 3D stacked memory devices limit memory capacity and performance due to heat dissipation challenges, as processor cores generate heat during operation, leading to increased power consumption and degradation of memory performance.

Innovation Solution

Address swizzling is employed in processing systems with stacked memory, where a single memory address is swizzled to access different physical locations on multiple memory dies, distributing heat generation and reducing hotspotting by alternating access patterns between memory banks or quadrants.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If 3D stacked memory is used to increase memory capacity and bandwidth, then memory capacity and communication between stacked dies are improved, but thermal issues and heat dissipation challenges worsen

Engineering Contradiction:
Improvememory capacityVSAvoidheat dissipation
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The memory address space is segmented and mapped to different physical locations across multiple stacked memory dies. By dividing the access pattern into separate spatial segments, the patent distributes heat generation across multiple dies rather than concentrating it in a single location, thereby improving thermal management while maintaining increased memory capacity through vertical stacking.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a dimensional transformation in address mapping, where linear address sequences are mapped to two-dimensional or three-dimensional physical layouts across stacked dies. This dimensional change allows access patterns that naturally distribute thermal load across the vertical stack, resolving the contradiction between increased capacity and heat dissipation challenges.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If multiple threads access stacked memory in parallel to increase bandwidth, then communication efficiency is improved, but thermal hotspots and localized heat generation worsen

Engineering Contradiction:
ImprovebandwidthVSAvoidthermal hotspots
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by assigning different access patterns to different threads based on their spatial distribution. Each thread is configured to access specific regions of the stacked memory, creating localized access patterns that prevent concurrent threads from generating heat at the same physical location. This maintains high bandwidth through parallel access while distributing thermal hotspots across different regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The address mapping scheme introduces asymmetry in how different threads access memory locations. By using asymmetric address-to-physical-location mappings, the patent ensures that parallel threads access different physical regions, distributing thermal load asymmetrically across the stack rather than creating symmetric hotspots, thereby maintaining productivity while reducing thermal concentration.

Inventive Principle:
Principle #4Asymmetry

3Power

If processor cores operate at high performance, then compute capability is improved, but power consumption and heat generation worsen

Engineering Contradiction:
Improvecompute capabilityVSAvoidpower consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful effect of concentrated heat generation into a beneficial distributed access pattern. By designing the address mapping to naturally spread out access patterns, the system transforms what would be concentrated thermal hotspots into distributed thermal patterns, allowing high-performance compute operations while improving thermal management and reducing localized power density issues.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP3701379B1Swizzling in 3D stacked memory
Publication Date: 2024.11.13 ADVANCED MICRO DEVICES INC
  • EP3701379B1 patent drawingFigure 1
  • EP3701379B1 patent drawingFigure 2~3
  • EP3701379B1 patent drawingFigure 4

AI summary

A processing system [100] includes a compute die [102] and a stacked memory [104] stacked with the compute die. The stacked memory includes a first memory die [104B] and a second memory die [104A] stacked on top of the first memory die. A parallel access using a single memory address is directed towards different memory banks [206, 208] of the first memory die and the second memory die. The single memory address of the parallel access is swizzled to access the first memory die and the second memory die at different physical locations.