Decompression Accelerator for CPU Core Bandwidth Bottleneck
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dynamic Random Access Memory (DRAM) and interconnect bandwidth limitations act as significant performance bottlenecks for CPU cores, causing delays in data transfer and hindering processor performance.
Innovation Solution
The implementation of a hardware-software synergistic solution that includes a low latency decompression accelerator located near the Level 2 (L2) cache of the processor core, enabling fine-grained decompression and reducing the latency associated with decompression operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data is transferred from DRAM to CPU core, then data transfer occurs, but DRAM and interconnect bandwidth limitations cause delays and performance bottlenecks
Solution Approach 1:
The patent extracts the decompression function from the main CPU core to a separate hardware decompression accelerator. This allows the CPU core to continue executing instructions while decompression operations are performed in parallel by the dedicated accelerator, eliminating decompression delays from the critical execution path and effectively increasing available bandwidth for compute operations.
Solution Approach 2:
The patent introduces a hardware decompression accelerator as an intermediary component between DRAM and the CPU core. This mediator handles the time-consuming decompression operations, allowing compressed data to be transferred efficiently from DRAM while the accelerator processes decompression in parallel, thus bypassing the bandwidth bottleneck for the main CPU pipeline.
2Ease of operation
If decompression is performed using software, then decompression functionality is achieved, but decompression latency increases and reduces processor performance
Solution Approach 1:
The patent replaces the software-based decompression mechanism with a hardware-based decompression accelerator. This substitution eliminates the interpretation overhead and sequential execution constraints of software, providing parallel hardware-level decompression that significantly reduces latency while maintaining full decompression functionality through dedicated hardware circuits.
3Device complexity
If decompression accelerator is located far from CPU core, then device complexity is reduced, but decompression latency increases
Solution Approach 1:
The patent positions the decompression accelerator in a different architectural dimension - integrated within the L2 cache hierarchy rather than as a separate external component. This spatial repositioning within the memory subsystem allows the accelerator to access compressed data directly from L2 cache with minimal latency, while the modular integration maintains manageable device complexity through standardized interface connections.
Data Source
AI summary
Methods and apparatus relating to an instruction and/or micro-architecture support for decompression on core are described. In an embodiment, decode circuitry decodes a decompression instruction into a first micro operation and a second micro operation. The first micro operation causes one or more load operations to fetch data into one or more cachelines of a cache of a processor core. Decompression Engine (DE) circuitry decompresses the fetched data from the one or more cachelines of the cache of the processor core in response to the second micro operation. Other embodiments are also disclosed and claimed.