Red Hat Virtualization allows a domain's virtual CPUs to associate with one or more host CPUs. This can be used to allocate real resources among one or more guests. This approach allows Red Hat Virtualization to make optimal use of processor resources when employing dual-core, hyperthreading, or other advanced CPU technologies. If you are running I/O intensive tasks, its typically better to dedicate either a hyperthread or entire core to run domain0. The Red Hat Virtualization credit scheduler automatically rebalances virtual cpus between physical ones, to maximize system use. The Red Hat Virtualization system allows the credit scheduler to move CPUs around as necessary, as long as the virtual CPU is pinned to a physical CPU.