At the end of July VMware published an interesting benchmark about its new vSphere 4.1 platform: over 171,000 concurrent users for a Microsoft Office SharePoint Server environment hosted by a single physical server.
The virtualization host was a Dell PowerEdge R710 2U rack server, powered by two Intel Quad-Core Xeon X5570 CPUs and 96GB RAM.
The SAN was an EMC CX3-40 SAN with two storage processors and 60 146GB hard drives (15K RPM).
vSphere 4.1 hosted five virtual machines: three Windows Server 2008 Datacenter Edition R2 IIS web servers, a SQL Server 2008 SP1 and SharePoint Server 2007 SP2.
The SQL Server VM was configured with 2 vCPUs and 16GB vRAM, the other VMs with 2 vCPUs and 4GB vRAM.
The workload, a mix of 80% read, 10% search, and 10% modify transactions, was generated by Microsoft Visual Studio Team System 2008 Test Agent.