Alibaba, Cisco, Dell EMC, Facebook, Google, Hewlett Packard Enterprise, Huawei, Intel and Microsoft have teamed up to form Compute Express Link (CXL), an open industry standard group for high-speed CPU interconnect.
CXL will maintain memory coherency between the CPU memory space and memory on attached devices, which allows resource sharing for higher performance, reduced software stack complexity, and lower overall system cost. The technology is built upon PCI Express (PCIe) infrastructure, leveraging the PCIe 5.0 physical and electrical interface to provide advanced protocol in three key areas:
- I/O Protocol
- Memory Protocol, initially allowing a host to share memory with an accelerator
- Coherency Interface
The group has completed work on a CXL Specification 1.0 for interconnect between the CPU and platform enhancements and workload accelerators, such as GPUs, FPGAs and other purpose-built accelerator solutions.