Intel and others launch Compute Express Link standard

A consortium of companies with interest in data centre and high-performance computing (HPC), including Facebook, Google, Intel, and Microsoft, have joined forces on a new interconnect specification for communication between central and co-processors: Compute Express Link.

Announced late yesterday, Compute Express Link (CXL) is a high-speed interconnect standard designed for CPU-to-device and CPU-to-memory communications focusing primarily on improving the performance of co-processor accelerators. As a result, there's little surprise to see the names involved: Intel, which offers a range of application specific integrated circuit (ASIC) and field-programmable gate array (FPGA) accelerators and will soon have its own range of discrete graphics processing unit (GPU) boards, leads the pack with Alibaba, Cisco, Dell's EMC subsidiary, Facebook, Google, Hewlett Packard Enterprise (HPE), Huawei, and Microsoft making up the remaining founding members. The most interesting absences: Nvidia, which offers GPU-based accelerator boards and recently splashed out on acquiring networking and interconnect specialist Mellanox, and Intel rival AMD.

The CXL specification itself, as ratified by the consortium, is based around the PCI Express (PCIe) 5.0 standard - using, in fact, the same physical and electrical interface - but adds new protocols designed to improve input and output performance, allow a host to share memory with a co-processor board, and a coherency interface to ensure that CPU and co-processor resources can be shared. The standard is open, the group claims, but available only to those who agree to join the CXL Consortium.

'CXL is an important milestone for data-centric computing, and will be a foundational standard for an open, dynamic accelerator ecosystem,' claims Intel's director of technology initiatives Jim Pappas of the standard. 'Like USB and PCI Express, which Intel also co-founded, we can look forward to a new wave of industry innovation and customer value delivered through the CXL standard.'

'Microsoft is joining the CXL consortium to drive the development of new industry bus standards to enable future generations of cloud servers,' adds Microsoft's Dr. Leendert van Doorn. 'Microsoft strongly believes in industry collaboration to drive breakthrough innovation. We look forward to combining efforts of the consortium with our own accelerated hardware achievements to advance emerging workloads from deep learning to high performance computing for the benefit of our customers.'

More information on Compute Express Link is available on the official website.