OK, thanks for two (helpful) answers - I'm assuming this really means that to get the benefit of all 4 cores an application would still need to be multi-core aware then, it would need to be presented with 4 vcpu's (which is effectively the 4 real cores). As an example, I have used 3D Studio Max on a quad core before, and when Rendering, all 4 cores go up to 90-100% cpu usage. It's nice and fast. Here in the office we often run database conversions using our own software, but as it's not multi-core available, it only ever puts one core to 90-100% usage, while the other 3 sit almost idle. Sounds like a VM would behave the same...?