Intel Prepping Linux For SNC6 With Six Nodes Per L3 Cache

Patches for the Linux kernel over the past week are preparing for an SNC6 sub-NUMA clustering mode. This is the first time I've seen patches or mentions of an SNC6 mode compared to SNC 1/2/3/4 modes with existing processors.

Sub-NUMA Clustering with Intel Xeon CPUs allows for each compute die to be exposed as its own NUMA domain. SNC3 with Granite Rapids can help some workloads compared to the HEX mode. Intel's convenient graphic of SNC3 mode vs. HEX with Granite Rapids Xeon 6900P:

The latest Linux kernel patch mentioning Intel SNC6 mode simply states:

x86/resctrl: Support Sub-NUMA cluster mode SNC6

Support Sub-NUMA cluster mode with 6 nodes per L3 cache (SNC6) on some Intel platforms.

Those Intel platforms with SNC6 mode aren't mentioned and I don't recall hearing of SNC6 explicitly before. Presumably it's for an upcoming Intel Xeon platform with a six tile compute die layout or otherwise breaking down a three tile compute die with half the memory channels and half the L3 cache per NUMA domain of SNC3 mode. Right now the only Sub-NUMA Clustering SNC6 search references I am seeing are around these Linux kernel patches, so we'll see with time more about the Intel SNC6 mode. In any event the Linux kernel is getting ready for Intel Sub-NUMA Clustering SNC6 support.