Effective CPU is the available CPU capacity for cluster VMs, after removing virtualization overhead (so CPU used by ESX hosts to provide virtualization resources).
Depending on vCenter version, vmware could use different formulas to compute cpu util at cluster level.
thanks but does BMC manipluate the value ? e.g. based on CLUSTER_FAILOVER_TOLERANCE or data from the esxhosts ? Or is it a traight vmware value