FYI, working on making a limited set of syscfg options available via sudo to allow users to swap around the MCDRAM Memory Mode and Memory Model, eg: syscfg /bcs "" "Memory Mode for 2LM" 1 syscfg /bcs "" "Memory Model" 4 syscfg /d biossettings "Memory Mode for 2LM" syscfg /d biossettings "Memory Model" [root@knl00 ~]# syscfg /d biossettings "Memory Mode for 2LM" Memory Mode for 2LM =================== Current Value : Flat -------------------- Possible Values --------------- Cache : 00 Flat : 01 Hybrid : 02 Auto : 03 [root@knl00 ~]# syscfg /d biossettings "Memory Model" Memory Model ============ Current Value : Quadrant ------------------------ Possible Values --------------- All2All : 00 SNC-2 : 01 SNC-4 : 02 Hemisphere : 03 Quadrant : 04 Auto : 05 So far, booting in Flat + Quadrant mostly hangs or at least takes a very very long time for the kernel to boot. Flat + All2All boots fine. Ben Some input based on Ben’s earlier questions: Flat mode (separate DDR and MCDRAM): syscfg /bcs "" "Memory Mode" 1 Cache mode: syscfg /bcs "" "Memory Mode" 0 The other setting is "Cluster Mode" where you choose between All2all, Quadrant and SNC4. Quadrant seems to be good starting point. All2all shouldn't be used as it is slower. You can see available values as usual: syscfg /d biossettings "Memory Mode" syscfg /d biossettings "Cluster Mode" Make sure it comes up as expected. numactl -H is the best way to tell. In flat mode you would see 2 NUMA nodes, #0 with DDR size and #1 with MCDRAM size. In cache mode you see single NUMA node with DDR size. For sub-numa clustering, SNC4+cache you see 4 NUMAs, and SNC4+flat you see 8 NUMAs. Let me know if you have any questions.