Next I wanted to simulate some load on the Exchange 2003 deployment. To do this I wanted to use the Microsoft LoadGen application, and install it on a temporary, dedicated Virtual Machine. I therefore deployed a new VM, and so that I wouldn't need to worry too much with the performance of the LoadGen machine itself, deployed it with twice the memory and CPU count as the Exchange 2003 back end. As it's only temporary VM, I don't need to worry about this high allocation eating into available resources too much.
You also need to install the 32-bit Exchange 2007 management tools available here.
With the simulated day well underway, I took another look at the perfmon.
Many hours later, the tests completed and a summary was presented.