SK hynix announces CXL 2 memory cards and SDK

SK hynix is sampling a CXL v2-connected memory product taking server memory past a terabyte and thereby catching up with Samsung.

CXL, the Computer eXpress Link, is a developing standard protocol to interconnect server CPUs, and their direct-attached memory, with accelerators and other high-speed peripherals, such as pools of DRAM or other memory types. Such external DRAM can be combined with a server’s local or near DRAM in a single and now larger memory pool.

SK hynix’ Uksong Kang, head of DRAM product planning, said: “I see CXL as a new opportunity to expand memory and create a new market. We aim to mass-produce CXL memory products by 2023. 

The company intends to continue to develop DRAM and advanced packaging technologies and then launch various CXL-based bandwidth/capacity expandable memory products.

SK hynix CXL 2.0 memory device.

SK hynix’ CXL memory device has 96GB capacity, composed of 24Gbit DDR5 DRAMs based on 1anm technology; the company’s latest tech node. It is packaged in the ES.3 EDSFF (Enterprise & Data Center Standard Form Factor) format and supports PCIe 5.0 x 8 Lane connectivity. A CXL controller connects the DRAM to the outside world. 

An SK hynix example shows an X86 CPU can have eight DDR5 channels with 768GB of DRAM ( 8 x 96GB DIMMs) and a total 260 to 320 GB/sec in bandwidth. CXL expansion adds in 4 x 96GB CXL memory cards. They add their bandwidth and capacity to the server, enabling it to reach a total of 1.15TB of memory and 360 to 480 GB/sec bandwidth.

SK hynix’s announcement was accompanied by supportive statements from Dell, Intel, AMD and Montage Technologies. 

Raghu Nambiar, corporate VP of Data Center Ecosystems and Solutions at AMD, said: “AMD is excited about the possibilities of workload performance acceleration with memory expansion using CXL technology. We look forward to collaborating with SK hynix on the development and validation of CXL as the industry shifts to a more dynamic and flexible memory infrastructure.”

SK hynix has also developed a Heterogeneous Memory Software Development Kit (HMSDK) for CXL memory devices that allows different grades of memory to be operated in one system. It has features to improve system performance and monitor the systems while running various workloads. SK hynix plans to distribute it as open source in the fourth quarter of 2022 to software developers.

Samsung announced an open-source Scalable Memory Development Kit (SMDK), which virtualises memory attached to the CXL interconnect, in October last year. It launched a CXL expander device in May 2022, with CXL 2.0 support. SK hynix is now catching up.

SK hynix will exhibit CXL 2.0 memory product product at the  Flash Memory Summit this month, Intel Innovation at the end of September and the Open Compute Project (OCP) Global Summit in October.