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. [1]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 [2]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.



[1] https://www.phoronix.com/review/xeon-6980p-snc3-hex

[2] https://lore.kernel.org/lkml/20241031220213.17991-1-tony.luck@intel.com/