CXL (Compute Express Link) Technology

Abstract

CXL (Compute Express Link) technology is a relatively new high-speed interconnect standard that was developed to enable faster communication between CPUs, GPUs, and other high-performance components in data center systems. This paper aims to provide a comprehensive technical overview of CXL technology, including its features, advantages, and potential applications in the modern data center environment. CXL Technology Research: CXL technology is based on Peripheral Component Interconnect Express (PCIe) and its extensions. CXL 1.0 is a switch-based interconnect architecture that operates on PCIe Gen5 electrical signaling, achieving data speeds of up to 32 Giga transfers per second (GT/s) per lane. CXL technology provides hardware-based support for cache coherency and memory semantics. CXL technology architecture consists of three main components: 1) CXL Devices: Devices that are compatible with the CXL interface can include processors, accelerators such as Graphics Processing Units (GPUs), and Smart Storage Devices; 2) CXL Switch: The switch enables communication between devices that support CXL. The switch can be external or embedded, allowing for more complex topologies; 3) CXL Memory: CXL memory devices support the CXL protocol for the efficient sharing of System memory.