I found this pretty fascinating, as someone who has been talking to several providers it certainly raises some pretty good points.
[..]Another of the challenges you’ll face along the way of Cloud is that of how to measure exactly what it is you are offering. But having a look at what the industry is doing won’t give you much help… as with so many things in IT, there is no standard. Amazon have their EC2 unit, and state that it is roughly the equivalent of 1.0-1.2GHz of a 2007 Opteron or Xeon CPU. With Azure, Microsoft haven’t gone down the same path – their indicative pricing/sizing shows a base compute unit of 1.6GHz with no indication as to what is underneath. Rackspace flip the whole thing on it’s head by deciding that memory is the primary resource constraint, therefore they’ll just charge for that and presumably give you as much CPU as you want (but with no indication as to the characteristics of the underlying CPU). Which way should you go? IMHO, none of the above.[..]
We need to have a standard unit of compute, that applies to virtual _and_ physical, new hardware and old, irrespective of AMD or Intel (or even SPARC or Power). And of course, it’s not all just about GHz because all GHz are most definitely not equal and yes it _does_ matter to applications. And lets not forget the power needed to deliver those GHz.
In talking with Terremark it seems their model is around VMware resource pools where they allocate you a set amount of Ghz for your account. They have a mixture of Intel dual socket systems and AMD quad socket systems, and if you run a lot of multi vCPU VMs you have a higher likelihood of ending up in the AMD pool vs the Intel one. I have been testing their vCloud Express product for my own personal needs(1 vCPU, 1.5GB ram 50GB HD), and noticed that my VM is on one of the AMD quad socket systems.