If you ever used SCVMM (System Center Virtual Machine Manager) 2008 R2, you might have notices different CPU Types under the Processor properties of each Virtual Machine or inside Hardware Profiles. You might wonder what these CPU Types are and how they could come into play while Virtual Processor scheduling is actually being handled by Hyper-V while you can’t find this option anywhere in Hyper-V management console?!!

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Well, this option is there just as a hint for SCVMM (when it doesn’t know anything about the Virtual Machine itself) to provide workload description for intelligent placement. For instance, if you create new VM you can say that you expect it to be equivalent of 2 proc 3.33 GHz Xeon with utilization of 40%. Placement will make sure that this VM is deployed on the right host that can provide enough CPU resources. Once VM is deployed and running, VMM will use historical performance information about this VM during migrations. Also note that CPU utilization parameter in “Customize Ratings” dialog is normalized to VM processor type. 

Here’s another example;

Let’s say you deploy a VM from the Library and in the placement page you customize the expected CPU load and set it to 100%, then depending on the VM’s CPU Type, the placement rating will change.

100% Expected CPU load (in placement page)

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If you change the CPU Type few times, you’ll see that placement will be modeled based on the load on that CPU Type. As you increase the speed of the processor, the host rating will go down.

Please note that your rating might be a little bit different based on your actual physical processor on your host machine. The test here was done on a single dual core 2.66GHz processor.

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In this case, We have modeled 2 x 3.6GHz HT VM on a host with a single dual core processor at 2.66GHz

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Hope this helped you understand this feature! So long….