Compute Express Link (CXL) is emerging as a pivotal technology in addressing the performance demands of artificial intelligence (AI), high-performance computing (HPC), and big data applications. As it is set in an era where data demands are escalating at an unprecedented pace, Compute Express Link (CXL) technology is set to redefine the landscape of data computing.

In this article, we will also explore how Amphenol's cutting-edge CXL-enabled interconnect solutions are reimagining the future of high-speed data computing. We will look at three different products from Amphenol that offer robust CXL capabilities that meet the evolving needs of modern data centers.

What is CXL?

Compute Express Link (CXL) is a widely endorsed industry standard designed to establish low-latency, cache-coherent connections among processors, accelerators, and memory devices. At a time of enormous demands, CXL emerges as a vital solution for the data center industry, effectively addressing significant memory challenges that hinder performance and efficiency. CXL effectively overcomes the limitations of traditional server memory hierarchies, enhances memory bandwidth to keep pace with increasing core counts, and optimizes resource utilization in accelerated computing environments.

CXL is an open standard interconnect technology that is built on the already established PCI Express® (PCIe®) interface. CXL addresses the growing demands of modern data centers, particularly for applications in artificial intelligence (AI) and machine learning (ML). By enabling a unified memory space, CXL allows devices to share resources dynamically, improving performance while simplifying memory management.

CXL's Role in AI, HPC, and Big Data

As enterprise and consumer applications of AI, HPC, and Big Data are increasing, let’s take a closer look at how CXL meets the evolving demands of these fields. 

  • Memory Performance: CXL addresses significant memory challenges faced by data centers, particularly the latency gap between direct-attached DRAM and SSD storage. This gap can severely hinder computing performance, especially in AI and HPC applications that require rapid data access. By providing low-latency, cache-coherent links, CXL enables faster processing and efficient memory utilization.
  • Resource Pooling: The technology allows for memory pooling, where multiple hosts can access shared memory resources dynamically. This capability is particularly beneficial for AI workloads that may require varying amounts of memory at different times. For instance, CXL 2.0 supports switching to enable multiple hosts to access a single memory pool without significant latency
  • Scalability: CXL 3.1 enhances scalability by introducing multi-tiered switching and peer-to-peer direct memory access. This means that as workloads increase or change, data centers can reconfigure memory resources on the fly, optimizing performance for both AI and big data applications
  • Compatibility with Existing Standards: CXL builds upon the established PCIe® standards, allowing seamless integration with existing hardware while providing enhanced capabilities. This compatibility simplifies software development and reduces costs associated with adopting new technologies

CXL Consortium

The CXL Consortium is an open industry group established in 2019 to develop and promote the Compute Express Link (CXL) standard. Founded by leading organizations such as Intel, Google, and Microsoft, the consortium aims to enhance data center performance by creating technical specifications that support emerging use cases in artificial intelligence (AI), high-performance computing (HPC), and big data applications. It fosters collaboration among industry stakeholders and ensures that the technology remains adaptable and relevant, driving innovation and efficiency in modern computing environments.

Looking ahead, the future of CXL is promising with ongoing developments like CXL 2.0 and CXL 3.0, which introduce advanced features such as multi-hop switching and enhanced memory-sharing capabilities.

Amphenol’s CXL solutions

Amphenol offers a range of innovative products designed to enhance the capabilities of Compute Express Link (CXL) technology, addressing the growing demands of modern data centers. They come in varied form factors and functionalities, including high-speed interconnects and edge computing optimizations. Each product is engineered to support CXL's unique requirements for high bandwidth and low latency, making them ideal for applications requiring efficient memory sharing and resource pooling. Let’s take a look at some of them:

EDSFF E1/E3 High-Speed Cable Assembly

EDSFF E1/E3 High-Speed Cable Assembly The Amphenol EDSFF E1/E3 High-Speed Interconnect is a new addition to the CXL solutions. It is designed to optimize performance in CXL-enabled systems and features a compact form factor. It is engineered to transmit both power and high-speed signals through a cable that directly connects to the main printed circuit board, to support EDSFF E1/E3 SSDs and CXL modules. This two-piece cable solution supports data transmission rates of up to PCIe® 5.0 32Gb/s. One end of this cable connector features EDSFF standard interface Mini Cool Edge 1C/2C connectors, while the opposite end allows for flexibility in connector form factor selection, including options such as MCIO, Multi-Trak, and Backplane connectors. This versatility makes the assembly suitable for a range of applications within high-speed computing environments, providing efficient connectivity solutions for modern data centers. Here are some of its major features:
  1. The interconnect supports X4, X8, and standard links as per PCI-SIG CEM specifications, providing excellent performance and additional options for high-bandwidth applications.
  2. High-speed pins attach directly to raw cable, eliminating PCB trace signal loss, and ensuring reliable data transmission.
  3. This solution offers cost savings for the entire system, effectively reducing PCB costs for both the motherboard and backplane.
  4. Amphenol provides a flexible supply chain for customers, allowing soldering to be done in parallel with the riser PCBA process, thereby streamlining production.
  5. The connector is RoHS compliant, meeting environmental, health, and safety requirements.

Cool Express Link™ EDSFF E3 2C PCIe® Gen 5/6 Cable Connectors

Amphenol's Cool Express Link™ comprises a series of EDSFF E3 2C Hybrid Orthogonal Press-fit PCIe® Gen 5/6 cable connectors that facilitate low-latency, high-bandwidth, and high-throughput data transmission for both current and next-generation storage solutions, including CXL 3.1 applications. These connectors are specifically designed for high-performance computing environments, particularly in artificial intelligence and machine learning, where advanced enterprise storage and coherent memory sharing are essential. Here are some of its core features. Cool Express Link™ EDSFF E3 2C PCIe<sup>®</sup> Gen 5/6 Cable Connectors
  1. The robust and orthogonal die-cast cage design provides a durable and reliable connection.
  2. The hybrid design routes power and sideband to the midplane, which simplifies midplane architecture and reduces overall system costs.
  3. This hybrid design also allows high-speed signals to overpass to the host side, meeting low latency and low loss requirements essential for applications in artificial intelligence (AI), machine learning (ML), and high-performance computing (HPC).
  4. The simple locking and latching feature makes it easy for operators to plug and unplug the cable, enhancing usability and operational efficiency.
  5. The E3 2C design is currently used in applications, with the ability to expand tooling to E3 4C for future applications, ensuring scalability as technology evolves.
  6. Its orthogonal high-density design supports a group of drives or devices in the front panel, optimizing space utilization in data centers.
  7. The separate connector and cable assembly design lowers maintenance costs by simplifying repairs and replacements, reducing downtime.
  8. Finally, the press-fit connector design eliminates SMT component height limitations, allowing for more flexible design options in compact spaces.

Hyper Cool Edge Connectors (SFF-TA-1037 PMM Connector)

Hyper Cool Edge Connectors (SFF-TA-1037 PMM connector) Amphenol's Hyper Cool Edge Connectors (SFF-TA-1037 PMM Connector) are designed to support the Pluggable Multi-purpose Module (SFF-TA-1034) by providing high-speed data transmission, sideband communication, and power delivery. These connectors feature a 0.6mm pitch and are optimized for various applications, including xPU, CXL, and NIC modules utilized in data centers, servers, storage systems, and AI or machine learning environments. Available in vertical, right-angle, and straddle mount configurations, as well as panel mount options for board-to-cable applications, these connectors offer versatility in installation.
  1. The 4C+ EP receptacle supports X16 PCIe® lanes, sideband, and 200W power, providing robust connectivity options that enable high-performance applications and efficient power delivery.
  2. With a 108-pin receptacle supporting an additional sixteen (16) Tx and Rx PCIe® lanes, this design enhances data throughput, making it suitable for demanding tasks that require high bandwidth.
  3. The 2-pin power receptacle supports up to an additional 400W, allowing for flexible power management and ensuring that connected devices receive adequate energy for optimal performance.
  4. This interconnect supports various board-to-board and cable module applications such as SSDs, NICs, and CXL-enabled modules making it versatile for multiple deployment scenarios in modern computing environments.
  5. It is designed to support xPU/CXL/NIC applications and modules, facilitating the integration of advanced processing units and accelerators into existing infrastructures.
  6. A common clock with options for SRIS and SRNS support by both host and device enhances synchronization across components, which is critical for maintaining data integrity during high-speed operations.
  7. The system supports single-ended, high-speed differential pairs up to 64G PAM4, with the capability to upgrade to 112G PAM4, ensuring future-proofing as bandwidth requirements continue to grow in high-performance computing applications.

PCI Express® Gen 6 Card Edge Connector

The Amphenol PCIe® Gen 6 Card Edge Connector is designed to support the latest advancements in high-speed data transmission, particularly for applications requiring substantial bandwidth and low latency. This connector is engineered for compatibility with PCIe® Gen 6 specifications. It is also backward compatible with and is footprint interchangeable with PCIe® 5/4/3/2/1.

Accommodating the increasing demands of modern computing environments, this connector finds extensive application in CXL smart memory controllers, data centers, AI, and machine learning applications, automotive infotainment systems, industrial and notebook PCs, embedded systems, and in the medical field such as respirators. Here are some of the features of this connector.

 PCI Express<sup>®</sup> Gen 6 Card Edge Connectors
  1. With high-performing data transmission rates of up to 64 GT/s, this connector meets PCIe® Gen 6 specifications for higher bandwidth and data rate system requirements.
  2. The PCIe Gen 6 Card Edge Connectors come in X1, X4, X8, and X16 and are available in a variety of positions, providing options to support different signal bandwidth requirements.
  3. It features the option to remove ridges, allowing for flexibility to meet application-specific needs.
  4. The connector includes side latch or locked latch options, adding an extra feature to secure the position of the mating card effectively.
  5. Its open-side wall feature accommodates longer mating cards, enhancing versatility in design.
  6. The connector uses low-halogen materials ensuring compliance with RoHS standards.

End Notes

We cannot imagine an immediate future without data centers and HPCs, and applications like AI and ML in it. We can confidently say that CXL will play a major role in it. The advancements in Compute Express Link (CXL) technology are reshaping the landscape of modern computing. As organizations increasingly demand efficient, scalable interconnect solutions, CXL emerges as a vital component for enabling seamless memory sharing, resource pooling, and enhanced performance. The ongoing developments in CXL, including future versions like CXL 2.0 and 3.0, promise to further enhance its capabilities and solidify its role as a cornerstone of data center infrastructure.

To explore how Amphenol's innovative product offerings can support your transition to CXL-enabled systems and help you stay ahead of industry trends, we encourage you to visit our product pages for detailed information on our cutting-edge interconnect solutions. You can also reach out to our 24/5 Live Chat Tech Team to learn more about our products!