AMD Linux EDAC Driver Prepares For Zen 4, RDDR5 / LRDDR5 Memory
In addition to recent work like preparing for up to 12 CCDs per socket, temperature monitoring, and other bits, out today is a set of patches for AMD's EDAC (Error Detection and Correction) driver code for the next-generation Zen 4 server processors.
The work sent out today includes adding support for RDDR5 and LRDDR5 memory support to the driver (conventional DDR5 support was already mainlined). This is for Registered DDR5 memory support as well as Load-Reduced DDR5 memory support. LRDDR5 support is for the higher memory density servers, similar to LRDIMMs with prior DDR generations.
The patches do also confirm up to twelve memory controllers per socket with the next-gen processors, compared to the current limit of eight.
With these additions being squarely for next-generation parts and RDDR5/LRDDR5, it does further solidify that Zen 4's Family/Model IDs as AMD Family 19h Models 10h-1Fh and A0h-AFh. These IDs were previously reported on Phoronix in relation to other Linux patches, which some doubted were accurate for Zen 4 given that it's Family 19h still, but is similar to what was seen with 17h for Zen/Zen+/Zen2, etc.
The patches are now out on the kernel mailing list for adding the new IDs and RDDR5/LRDDR5 support to the AMD EDAC driver and in turn will likely be mainlined for the upcoming 5.17 cycle given no surprises.