Implied Directory State Updates for Cache-Line Request Handling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As computing systems evolve with increased processing power and complexity, existing interconnect architectures struggle to meet the demands for high-performance communication and power efficiency across multiple processors and devices, particularly in high-performance computing environments like servers and mobile ecosystems.
Innovation Solution
A new High Performance Interconnect (HPI) architecture is introduced, featuring a layered protocol stack with transaction, link, and physical layers, supporting point-to-point links and credit-based flow control, enabling efficient data transfer and power management across multiple devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional multi-drop buses are used for interconnect, then electrical communication is simplified, but communication speed and performance are limited
Solution Approach 1:
The patent segments the interconnect architecture from traditional multi-drop buses into point-to-point links with separate request and response channels. This segmentation enables independent optimization of each channel, allowing higher communication speeds while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent introduces a new dimension to the interconnect architecture by implementing full-duplex point-to-point links with separate request and response channels, transitioning from the traditional single-channel multi-drop bus approach. This dimensional change enables simultaneous bidirectional communication, dramatically increasing communication speed and throughput.
2Power
If processing power is increased with multiple cores and sockets, then computing capability is improved, but communication between sockets becomes more critical and complex
Solution Approach 1:
The HPI interconnect architecture provides a universal point-to-point link design that can be scaled to connect any number of processors, cores, and devices. The same basic link structure handles both request and response traffic, as well as supporting various transaction types, reducing overall system complexity despite increased computing power requirements.
Solution Approach 2:
The patent introduces an intermediary credit-based flow control mechanism that mediates communication between multiple processors and devices. This intermediary system manages the complexity of multi-socket communication by providing standardized protocols for data transfer, error handling, and flow control, making the system manageable despite increased computing power.
3Productivity
If data transfer rate is increased to meet processing demands, then performance is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic credit-based flow control where data transfer occurs in controlled bursts rather than continuous operation. The credit system allows the interconnect to operate at high speeds when credits are available while entering lower-power states when buffers are full or empty, reducing overall power consumption while maintaining high data transfer efficiency during active periods.
Solution Approach 2:
The HPI architecture dynamically adjusts data transfer rates based on buffer credit availability and traffic conditions. The interconnect can operate at maximum speed when demand is high and credits are available, then scale back to lower power consumption modes when traffic is light or buffers are full, optimizing the balance between productivity and power usage.
Data Source
AI summary
A request is received over a link that requests a particular line in memory. A directory state record is identified in memory that identifies a directory state of the particular line. A type of the request is identified from the request. It is determined that the directory state of the particular line is to change from the particular state to a new state based on the directory state of the particular line and the type of the request. The directory state record is changed, in response to receipt of the request, to reflect the new state. A copy of the particular line is sent in response to the request.