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.

The vRAM capacity of a vSphere 5.0 license key equals the vRAM entitlement of the license edition multiplied by the processor capacity of the license key. For example, vSphere 5.0 Standard entitles to a 32GB of vRAM. A license key of vSphere 5.0 Standard with capacity for 10 processor entitles to a vRAM capacity of 320GB.

The amount of vRAM that vSphere 5.0 license keys provide is aggregated into vRAM pools for every license edition when the license keys are assigned to ESXi 5.0 hosts.

The vRAM usage equals the sum of memory that is configured on powered-on virtual machines that run on ESXi 5.0 hosts. The vRAM usage is calculated for every vRAM pool that is available in a vCenter Server system or a Linked Mode group.

No restriction exist for the number of virtual machines that can consume the available capacity in a vRAM pool. No restriction exists on how virtual machines are distributed across all hosts in a vRAM pool either. However, you must maintain the ESXi 5.0 in your environment in compliance with the vSphere 5.0 licensing model.

If the amount of vRAM that is available in the vRAM pools in your virtual environment is insufficient, you can extend the vRAM pools to keep them in compliance with the licensing model of vSphere 5.0 products.