Shader Engine Store Bandwidth Compression

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Solution Overview

Problem

Graphics processing units (GPUs) face memory bandwidth limitations due to the high number of threads executing simultaneously, leading to unprocessed read/write requests accumulating at the frame buffer interface, which substantially limits memory-related performance.

Innovation Solution

A method is introduced to compress data for thread group STORE operations by determining if thread group data is compressible and reducing it into fewer subpackets, allowing it to be written to the frame buffer memory in one clock cycle, thereby improving memory performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple threads execute simultaneously in a thread group, then processing throughput is improved, but memory bandwidth requirements increase excessively

Engineering Contradiction:
Improveprocessing throughputVSAvoidmemory bandwidth consumption
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent merges the memory operations of multiple threads within a thread group by compressing their individual scalar write operations into a single compressed memory transaction. The compression engine combines data from multiple threads and transmits it as one memory operation, reducing the total number of memory transactions while maintaining the processing throughput of multiple simultaneous threads.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the data representation parameter by compressing scalar data from multiple threads into a reduced representation that can be transmitted in fewer memory transactions. The compression algorithm transforms the raw scalar data into a compressed format that maintains semantic information while reducing bandwidth consumption and transaction count.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If scalar data is written to frame buffer memory individually by each thread, then data accuracy is maintained, but memory bandwidth is insufficient

Engineering Contradiction:
Improvedata accuracyVSAvoidmemory bandwidth
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The compression engine merges individual scalar write operations from multiple threads into a single compressed memory transaction. It collects scalar data from all threads in the thread group and transmits it as one memory operation, maintaining data accuracy while significantly reducing memory bandwidth requirements and transaction overhead.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a compressed representation copy of the scalar data that preserves the essential information needed for frame buffer rendering. The compression algorithm generates a reduced representation that can be decompressed or directly interpreted by the memory system, maintaining data fidelity while reducing bandwidth consumption.

Inventive Principle:
Principle #26Copying

3Reliability

If thread group data is transmitted uncompressed, then data integrity is preserved, but memory performance is limited

Engineering Contradiction:
Improvedata integrityVSAvoidmemory performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the data transmission parameter by compressing thread group data before memory transmission. The compression engine transforms the data into a compact representation that maintains integrity through deterministic decompression, thereby improving memory performance (fewer transactions, lower latency) while preserving data integrity for correct frame buffer rendering.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS7886116B1Bandwidth compression for shader engine store operations
Publication Date: 2011.02.08 NVIDIA CORP
  • US7886116B1 patent drawing
  • US7886116B1 patent drawing
  • US7886116B1 patent drawing

AI summary

Embodiments of the present invention set forth systems and methods for compressing thread group data written to frame buffer memory to increase overall memory performance. A compression/decompression engine within the frame buffer memory interface includes logic configured to identify situations where the threads of a thread group are writing similar scalar values to memory. Upon recognizing such a situation, the engine is configured to compress the scalar data into a form that allows all of the scalar data to be written to or read from the frame buffer memory in fewer clock cycles than would be required to transmit the data in uncompressed form to or from memory. Consequently, the disclosed systems and methods are able to effectively increase memory performance when executing thread group STORE and LOAD operations.