That's the point. It shouldn't matter but in fact it does. You can see this for yourself if you use the x86_64 optimizations on VM's in benchmark tests. And

That's the point. It shouldn't matter but in fact it does. You can see this for yourself if you use the x86_64 optimizations on VM's in benchmark tests. And you will see various results depending on hypervisor used and what application is used. This will even change with time as updates are made to each hypervisor. What I am describing is exactly what is not supposed to happen which is why you are struggling to think of a situation where this should matter. You are being entirely logical.