At FMS 2024, we saw the SMC 2×00 CXL memory controller, along with several devices that it powers. Not only did we see a few more traditional memory expansion devices, but we also saw a fascinating non-volatile memory module from SMART.
Microchip SMC 2×00 CXL Memory Controller and Devices
Here is the controller shown at the show. The little placard says it is a CXL 2.0 DDR4 or DDR5 memory controller.
Here is a closer shot of the chip.
Microchip also had a few devices. One is a Micron CZ120 that we have seen before. The SMART CMM-E3S is a 128GB E3.S module.
The most interesting one, however, might be the DDR4 ECC module, which has its own energy source to be used as a non-volatile DRAM source. This is really cool since it could potentially be an option to replace NVDIMMs in systems.
Here is a more traditional DIMM solution where the memory is installed on a PCIe card.
There was also a Longsys 512GB CXL Memory Expansion Module. This card was absolutely huge. At the same time, adding eight DIMMs per card and then multiple cards per system is a neat way to add a lot of memory.
CXL was featured more at FMS 2024, so this was great to see.
Final Words
With the 2H 2024 processors, we are going to hear a lot more about CXL 2.0 as that is a key feature. We thought this one was a fun one so we wanted to show the Microchip SMC 2×00 controller devices. This has come a long way since we covered the Microchip SMC 1000 For The Serial Attached Memory Future designed for IBM devices.
How about latency with CXL-RAM?
@Pat
It depends on the architecture of CXL, whether you’re using switches and so on. I’d expect commercial simple (directly attached to the CPU accessing it) device latency to be 1.5 to 3.0x the latency of local DRAM.
You can find a list of papers analyzing this topic at 0x10.sh/the-performance-of-cxl-memory-latency-bandwidth