ESXi 5.0 hosts are licensed with vSphere 5.0 license keys. vSphere 5.0 license keys have per-processor capacity with pooled vRAM entitlements. vRAM entitlements of vSphere 5.0 licenses are pooled across all assigned vSphere 5.0 license keys of the same product edition for a single vCenter Server system or for a Linked Mode group.

Each vSphere 5.0 license key has a certain processor capacity that you can use to license multiple physical processors on ESXi hosts. When you assign a vSphere license key to a host, the amount of processor capacity that is consumed is equal to the number of physical processors in the host.

Every vSphere 5.0 edition includes a vRAM capacity entitlement. vRAM entitlements are pooled across all assigned vSphere 5.0 licenses of the same edition for a vCenter Server instance or in a Linked Mode group. Only powered-on virtual machines consume vRAM capacity in an amount that is equal to the sum of their configured memory.