AMD Virtualization

Virtualization is the new must-have feature, especially for server and workstation users. While Intel has included hardware support for virtualization in most Core 2 processors, lower-end Core 2 processors do not come with virtualization support. In contrast, all Barcelona processors will have hardware support for virtualization.

AMD is eager to let us know that while processors from both AMD and Intel will support virtualization, their implementation will be far superior. If that is true, then they will be able to offer a truly compelling processor for server and workstation users to consider. Take a look at this comparison of the Intel Core 2 architecture versus AMD's new Barcelona architecture :

According to AMD, their monolithic design, integrated memory controller with DEV support and tagged TLB (Translation Lookaside Buffer) will allow their quad-core Opteron to outperform Intel processors in virtualization.

Nested Paging

The Barcelona also supports nested paging, which as AMD points out, is not supported by Intel's Core 2 processors. So what is nested paging, and what's the big deal?

In the standard paging mode, virtual machines can only access their memory pools through the help of the hypervisor. This means they can only do so one at a time. To improve performance, nested paging can be used to allow virtual machines to bypass the hypervisor and directly access their memory pools.

As we understand it, nested paging does not allow the virtual machines to bypass the hypervisor all the time. It does so under certain circumstances, but the performance advantage is significant.