Narrow Block Floating-Point Activation Compression for Backpropagation

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Solution Overview

Problem

Machine learning models, particularly neural networks, are computationally expensive and inefficient for real-time processing due to their high computational demands, especially when trained and executed on general-purpose processors.

Innovation Solution

Storing activation values from neural networks in a compressed block floating-point format during forward and backward propagation, using quantized or narrow block floating-point formats to reduce precision and memory requirements, and employing specialized hardware like FPGAs for accelerated processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If activation values are stored in full precision block floating-point format, then accuracy is maintained, but memory usage and computational overhead increase

Engineering Contradiction:
Improveactivation value precisionVSAvoidmemory usage
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent changes the precision parameter of activation values by converting them from full precision block floating-point format to a compressed format with lower precision. This is achieved through quantization and compression operations that reduce the number of bits required to represent each activation value, thereby reducing memory usage while maintaining sufficient accuracy for neural network training operations.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If general-purpose processors are used for neural network training, then flexibility is maintained, but computational speed and energy efficiency deteriorate

Engineering Contradiction:
Improveprocessor flexibilityVSAvoidcomputational speed
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the neural network training process into distinct phases (forward propagation, backward propagation) and applies different precision formats to different phases. During forward propagation, full precision is used to maintain accuracy, while during backward propagation, compressed lower-precision formats are used to accelerate computation and reduce memory bandwidth requirements, thereby improving overall computational speed while maintaining flexibility.

Inventive Principle:
Principle #1Segmentation

3Reliability

If full precision formats are used during forward and backward propagation, then training accuracy is maintained, but computational complexity and energy consumption increase

Engineering Contradiction:
Improvetraining accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent dynamically adjusts the precision format of activation values based on the phase of training. During forward propagation, full precision block floating-point format is used to ensure accurate computation of activations. During backward propagation, the system transitions to a compressed lower-precision format for gradient computations, thereby reducing energy consumption while maintaining sufficient training accuracy through selective precision management.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS12443848B2Neural network activation compression with narrow block floating-point
Publication Date: 2025.10.14 MICROSOFT TECHNOLOGY LICENSING LLC
  • US12443848B2 patent drawing
  • US12443848B2 patent drawing
  • US12443848B2 patent drawing

AI summary

Apparatus and methods for training a neural network accelerator using quantized precision data formats are disclosed, and in particular for storing activation values from a neural network in a compressed format for use during forward and backward propagation training of the neural network. In certain examples of the disclosed technology, a computing system includes processors, memory, and a compressor in communication with the memory. The computing system is configured to perform forward propagation for a layer of a neural network to produced first activation values in a first block floating-point format. In some examples, activation values generated by forward propagation are converted by the compressor to a second block floating-point format having a narrower numerical precision than the first block floating-point format. The compressed activation values are stored in the memory, where they can be retrieved for use during back propagation.