Compute Express Link (CXL) is an open industry interconnect
standard for providing high bandwidth and low latency. It adds
connectivity between host processors, accelerators, memory devices,
and network interface cards (NICs). CXL also enables memory
expansion and acceleration across high-performance computational
workloads for AI, ML, HPC, and communications segments. CXL
uses PCIe Gen 5.0 PHY based high-speed serial link to communicate
between the latest generation of CPU processors.
SMART develops CXL Type 3 (CXL.mem) memory products to
address the industry’s need for more memory per processor core.
The CXL interconnect specification allows for a significant expansion
of memory form factor options leveraged from SSDs. SMART’s
introductory CXL Memory Modules known as XMM’s are offered in
the E3.S form factor.
Memory Modules (XMM)
Key Features
•
CXL-2.0 compatible with PCIe-Gen5 speeds running at 32GT/s
•
Available in 64GB DDR5 memory capacity with expansion
plans up to 256GB in the future
•
Supports Reliability, Availability and Serviceability (RAS)
features added in CXL-2.0
•
Available in EDSFF E3.S 2T (2U short) form-factor.
•
Powered by only 12V supply from EDSFF compatible edge
interface (SFF-TA-1009)
•
Supports sideband interfaces for real-time debug,
management and system update, enabling out-of-band
management of the module
•
Supports additional security features to protect data from side-
channel attacks
Why choose SMART Modular for CXL?
•
SMART is a contributing member of the CXL consortium,
closely collaborating with CPU and silicon suppliers to test for
compatibility and feature completeness.
•
SMART has PCB design, test and assembly expertise to develop
high speed memory and storage modules in variety of form-
factors like DIMMs, E1.S, E3.S and PCIe add-in cards (AICs).
•
SMART’s global manufacturing footprint and strong relationships
with components suppliers minimizes disruption even in stringent
supply-chain conditions.
•
Customers can leverage SMART’s test and validation service for
pre-screening memory modules for reliability and quality.
•
SMART’s experience in other interconnect standards and
technologies like Gen-Z, OpenCAPI and persistent memory
solutions such as NVDIMM-N.
For more information, please visit: www.smartm.com
Customer Service:
T: (+1) 510-623-1231 • E: customers@smartm.com
Headquarters/North America:
T: (+1) 800-956-7627 • T: (+1) 510-623-1231
F: (+1) 510-623-1434 • E: info@smartm.com
Latin America:
T: (+55) 11 4417-7200 • E: sales.br@smartm.com
EMEA:
T: (+44) 0 7826-064-745 • E: sales.euro@smartm.com
Asia/Pacific:
T: (+65) 6678-7670 • E: sales.asia@smartm.com
©2022, SMART Modular Technologies, All rights reserved. The stylized “S” in conjunction with “SMART”, as well as “SMART Modular Technologies” are registered trademarks of SMART Modular Technologies. All other trademarks are
the property of the respective owners. These materials are provided by SMART Modular Technologies as a service to its customers and may only be used for informational purposes. 07.20.22/CXL/Rev.4
Need for CXL
With addition of more cores per CPU socket,
Memory per core is becoming bottleneck for
scaling system performance. With limited PCB
real estate there is no room to add more DIMM
slots, or add new pins on CPU socket for DDR
channels. The choice is simple to move Memory
to serial interfaces like PCIe. However, PCIe
is designed for large bulky Data transfers for
IO devices. Therefore, CXL uses existing PCIe
Physical layer to enable low latency, cache line
granular access to connect Memory over serial
bus directly addressable memory.
CPU
CPU
DDR5 NVDIMM
Ordering Information
CXL Memory Module (XMM)
SMART Part Number Description
STXAB64GRMBF4S40SB 64GB CXL-2.0 Memory modules in E3.S 2T form-factor with dual ranks/channel DDR5
STXAB96GRMBF4S40SB 96GB CXL-2.0 Memory modules in E3.S 2T form-factor with dual ranks/channel DDR5
Contact: Arthur Sainio at Arthur.Sainio@smartm.com for any sales and sampling queries.
Current Gen Next Gen
Cores per CPU 64 cores 120 cores
Direct attached Memory (DDR4/5) 8Ch x 2 DPC x 128GB = 2048GB (2TB) 12Ch x 2 DPC x 128GB = 3072GB (3TB)
Serial attached Memory (CXL) 0 (Not supported) 8 x 256GB = 2048GB (2TB)
Total Memory 2048GB (2TB) 5120GB (5TB)
Memory per Core 32GB per core 42.6GB per core