Zero-Bandwidth Clears for Graphics Buffer Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional graphics processing systems are limited by the bandwidth between the graphics processor and external memory, particularly during clear operations for color and z values, leading to inefficient memory accesses and cache usage.
Innovation Solution
The implementation of zero-bandwidth-clears, where clear values are stored in the graphics processor, allowing regions of color or z buffers to be cleared without writing to or reading from external memory, using zero-bandwidth-clear commands that reference stored clear values, thereby reducing memory accesses and conserving cache storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clear operations write to external memory, then buffer regions are properly cleared, but memory bandwidth is consumed and access time increases
Solution Approach 1:
The patent segments the clear operation into two parts: (1) storing clear values in on-chip memory structures within the graphics processor, and (2) generating clear commands that reference these stored values without writing to external memory. This segmentation allows the clear operation to be performed efficiently by eliminating external memory writes while maintaining buffer clear completeness through proper tracking of clear value references.
Solution Approach 2:
The patent performs preliminary action by pre-storing clear values in on-chip memory structures before they are needed for clear operations. This allows the clear values to be readily available when clear commands are executed, eliminating the need to read them from external memory during the actual clear operation, thus improving rendering performance.
2Quantity of substance
If clear values are stored in external memory, then memory is available for general use, but cache storage is wasted and access speed decreases
Solution Approach 1:
The patent introduces on-chip memory structures as an intermediary between external memory and the clear operation logic. Clear values are stored in this intermediate on-chip memory, which provides fast access during clear operations while external memory remains available for general graphics data storage. This intermediary storage eliminates the trade-off by providing both fast access and external memory availability.
3Adaptability or versatility
If clear operations access external memory, then clear values can be updated, but bandwidth is consumed and clock cycles are lost
Solution Approach 1:
The patent implements feedback mechanisms through clear command processing that tracks which buffer regions are cleared to which values. This feedback system allows the graphics processor to determine when stored clear values are no longer referenced by any active buffer regions, triggering an update of the clear values in on-chip memory from external memory. This feedback-based update approach minimizes external memory accesses while maintaining adaptability.
Data Source
AI summary
A system and method for performing zero-bandwidth-clears reduces external memory accesses by a graphics processor when performing clears and subsequent read operations. A set of clear values is stored in the graphics processor. Each region of a color or z buffer may be configured using a zero-bandwidth-clear command to reference a clear value without writing the external memory. The clear value is provided to a requestor without accessing the external memory when a read access is performed.