Question : How does virtualization make Intel Xeon Server processors more efficient?
I understand the concept of virtualization but I still don’t understand how it saves energy? How does it make the Xeon Server processors more efficient? Any help would be greatly appreciated.
virtualization

Best answer:

Answer by Trix
Well, it may not -always- make CPU utilisation more efficient, but it often does. By the way, it’s not just Xeon that benefits from virtualisation – most modern server-class CPUs will gain efficiencies.

If you look at the CPU usage of a standard server, you will generally not see it being 100% (or even 80%) utilised. That’s a lot of idle time for a server that is sucking power to run the CPU, the fans, the memory, etc etc.

By running a bunch of virtual machines on a server with a decent amount of memory, you can get your servers sharing the CPU and possibly running at consistently 80% utilisation. Instead of having 5 servers using 10-15% utilisation, you have them all sitting on the one host, thus consuming a fraction of the resources and making much better use of the hardware.

However, virtualisation isn’t much use if you only need to run one server, or, conversely, you are running extremely heavy applications like databases or graphics rendering engines. For a very heavy dedicated server, running a virtualisation layer on top is not going to help you much (unless you’re looking at high-availability and/or load-balancing)