Optimizing ESX’s performance is one of the primary tasks of a system administrator. One wants to make the best use of what ESX can
offer not only in terms of its features but also their associated performance. Over time a number of customers have been asking us for a single comprehensive ESX performance tuning guide that would encompass its CPU, memory, storage, networking, resource management and DRS, component optimizations. Finally we have the Performance Tuning Best Practices for ESX Server 3  guide.

As indicated above this paper provides a list of performance tips that cover the most performance-critical areas of Virtual Infrastructure 3 (VI3). The paper assumes that one has deployed ESX and has a decent  working knowledge of both ESX and its virtualization concepts, and are now looking forward to optimizing its performance.

Some customers will want to carefully benchmark their ESX
installations, as a way to validate their configurations and determine their
sizing requirements. In order to help such customers with a systematic
benchmarking methodology for their virtualized workloads, we’ve added a
section in the paper called "Benchmarking Best Practices". It covers the
precautions that have to be taken and things to be kept in mind during such
benchmarking. We’ve already published a similar benchmarking guidelines
whitepaper for our hosted products Performance Benchmarking Guidelines for VMware Workstation 5.5

The strength of the paper is that it succinctly
(in 22 pages) captures the performance best practices and benchmarking tips
associated with key components. Note that the document does not delve into the
architecture of ESX nor provide specific performance data for the discussions.
It also doesn’t cover sizing guidelines or tuning tips for specific
applications running on ESX.

All of us from the Performance team hope you find the document useful.