Today's guest post is from VMware performance guru Scott Drummonds. Scott blogs over at communities (Virtual Performance blog) and the VMware Communities Performance section. Scott's talking about our latest feat of showing how virtual can be better than physical,  VMware Infrastructure Sets World Record for Web Server Performance

Building Block Architecture for Superior Performance

If any of you have heard me speak in the numerous events I've done in
the past two years, you may have heard me detail the areas where
virtualization performance can exceed native. There are scalability
limitations in traditional software that make nearly every enterprise
application fall short of utilizing the cores that are available to
them today. As the core explosion continues, this under-utilization of
processors will worsen. Here is a graph that we've been showing to
illustrate that point:

In 2008 I visited VMworld Europe and showed on using multiple virtual
machines on a single physical host could circumvent the limitations in
today's software. In that experiment we showed that 16,000 Exchange mailboxes could be fit on a single physical server
when no one had ever put more than 8,000 on in a single native
instance. We called this approach designing by "building blocks" and
were confident that as the core count continued to increase, we'd
continue to expose more applications whose performance could be
improved through virtualization.

On Thursday last week SPEC accepted VMware's submission of a SPECweb2005 result. And last night we posted an article on VROOM!
detailing the experiment and providing information on the submission.
This submission is an incredible first for us: not only have we shown
that we can circumvent limitations in web servers, but we posted a
world record performance number in the process. Of course, if any of
you have seen Sreekanth Setty's presentation at VMworld on his ongoing
work on SPECweb2005, this result wouldn't surprise you:

Getting a benchmark standardization body like SPEC to approve these
results isn't always easy. Most of the industry remains stuck in a mode
of thinking of performance as a single instance's maximum throughput.
But given the scale-out capabilities of a large number of enterprise
applications I'd argue that benchmarking should account for scale-out
capabilities on a single box. VMware's customers follow this practice
faithfully in sizing their deployments to match their needs and
everyone wants to know the platform's ability to handle this use-case.
SPEC's willingness to accept results showing building blocks on a
single host is commendable and progressive. As more benchmarks approve
submissions like these VMware will continue to be able to show record