Need to test the potential scalability or performance of your VMWare virtual environment? Then this tool from VMWare will possibly fit the bill;
VMmark is a free tool VMWare provides that enables you to assess the performance of a physical host when running a variety of workloads. These different workloads are referred to as ’tiles’ as is demonstrated by this diagram;
This method can be used for testing the scalability of a single workload, multiples of a single type of workload, or a variety of workloads. All of which may be the use case you need to understand prior to deployment or changes in requirements.
If you are looking to specify new hardware or understand the harware requirements of upcoming projects there are VMmark results for many server types and configurations already uploaded here;
This is a great reference for understanding real world server performance from actual users and companies other than VMWare.