5. Creating and Managing vApps : 5.4 vApp Deployment Readiness : 5.4.1 vApp Design Considerations : 5.4.1.2. vApp and Virtual Machine Hardware Version Considerations
   
5.4.1.2. vApp and Virtual Machine Hardware Version Considerations
Virtual machine hardware version 9 is supported in vSphere 5.1. This support is carried over to vCloud Director. For maximum configuration values, see VMware Configuration Maximums (VMware vSphere 5.0) (http://www.vmware.com/pdf/vsphere5/r50/vsphere-50-configuration-maximums.pdf). The major use cases for using hardware version 9 are:
*Windows 8 XP modeXP mode allows a virtualized Windows XP instance to run on Windows 8 for compatibility with older applications that do not run natively on Windows 8. Users running XP mode in Windows 8 must choose an organization virtual datacenter that is backed by a provider virtual datacenter with support for virtual hardware version 9. After adding support for virtual hardware version 9, you must also enable the Nested HV feature.
*64-bit nested virtualizationHyper-V and virtualized VMware vSphere ESXi™ nested virtualization can be helpful for non-production use cases, such as training and demonstration environments. Virtualized Hyper-V or virtualized ESXi running nested 64-bit virtual machines requires virtual hardware version 9 with the Nested HV feature enabled.
*CPU-intensive workloadsRunning a CPU-intensive workload in a virtual machine requiring between 32 and 64 vCPUs requires virtual hardware version 9.