* Which CPU features are required
* Which CPU features can be utilized (but are not required)
* Which CPU features can be virtualized—that is, made available to software running in the virtual machine
With a better understanding of how CPU features are required, used, and virtualized by VMware ESX, you can reason more precisely about what can be virtualized, what performance levels may result for a given combination of CPU, guest operating system, and version of VMware ESX, and how workloads may respond to adjusting configuration parameters both for software running in the virtual machine and at the VMware ESX level.
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