10g/11gR1 Processes = 25 + (10 + [max number of concurrent database file creations, and file extend operations possible])*n 11g.2.0.3 In 11.2.0.3, the "PROCESSES" parameter will be default to "available CPU cores * 80 + 40" (in the ASM spfile). As the default value for "MEMORY_TARGET" is based on "PROCESSES", it can be insufficient if there is a large number of CPU cores or large number of diskgroups which could cause issues (i.e. Grid Infrastructure stack fails to stop with ORA-04031 etc) per Bug:13605735 & Bug:12885278, it is recommended to increase the value of MEMORY_MAX_TARGET & MEMORY_TARGET before upgrading/installing to 11.2.0.3 (does not apply to 10g ASM):