vMotion between AMD and Intel CPUs

Can I vMotion a VM from an Intel to AMD server? It’s one of the big things that you have to learn about a VMware cluster, that vMotion cannot be performed between an AMD and Intel CPU – but this is only true when the virtual machine is running. If your VM is powered down, then you can move a VM between Intel CPUs and AMD CPUs.

You just need to know how.

You may want to read an article I wrote that refers to the impact that choosing the EVC mode has on performance, and one important point is that EVC (Enhanced vMotion Control) will mask off features and capabilities of the physical CPU from the capabilities used by the virtual CPU in the VM. With EVC, these capabilities are masked at the hypervisor level within the cluster, but they are also recorded within each VM as a CPU-ID mask. You can read the “EVC and CPU-ID FAQ” in KB 1005864.

You might get an error like;

Host CPU is incompatible with the virtual machine's requirements at CPUID level 0x1 register 'eax'
Host bits: 0000:0000:0000:0000:0010:0000:0110:1111:0010
Requried: 0000:0000:0001:xxxx:00xx:1111:xxxx:xxxx
If possible, use a cluster with Enhanced vMotion Compatibility (EVC) enabled

When you try to vMotion a powered on machine

How do I vMotion a VM between AMD and Intel CPUs?

Here are the steps required if you are migrating a VM from Intel to AMD or moving a VM from AMD to Intel CPU.

1. Power off the virtual machine.
2. Open the virtual machine properties and navigate to CPU, expand the CPU item
   
3. Press “Advanced” next to the “CPUID Mask” item
4. You will now see a new dialog, listing the CPU ID Mask settings. To enable migrating this VM to another CPU family, press the “Reset all to Default” button
   
5. Then, before powering the VM back on, migrate it to the new host.

This will let you move a VM from one CPU family to another. You can use the same technique when moving from a new CPU family to an older generation.

Are you interested in what the CPU ID Mask does and what it means – look at  some samples of CPU-ID and what it does in VMware KB 1993