And a follow up question- if I implement a large /tmpfs - shm, I can still use choose to not use AMM and use hugepages, correct ? From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Crisler, Jon Sent: Wednesday, July 21, 2010 11:57 AM To: oracle-l@xxxxxxxxxxxxx Subject: 11g AMM tmpfs vs hugepages for best overall performance Which is better for performance on large Red Hat 5 systems (64gb+ memory, 8+ cpu's) - using 10g style shm settings and hugepages, OR the newer 11g Automatic Memory Manager (which does not support hugepages). The system I am building is a 6 node 11g R1 RAC, memory somewhere between 64gb and 256gb (not sure yet), 8 cpu per node. This machine will support a huge workload.