*update* I've created a multithreaded version, stressing multi core / vSMP VMs. Check it out here: CPUBusiest
Remember the good 'old CPUBusy script used during the VMware Install & Configure training? Well I wanted to have something which allows you to control the load. So I created this little piece of software called CPUBusier.
The slider allows you to control how many sines to calculate per second. Start/Stop button to start/stop the load (duh) and 'Options...' to control the maximum amount when the slider is to the far right.
Here is a demo, gradually moving the slider to the right on my laptop. Note: to get this figure, set affinity to only one CPU in Windows task manager.
Did you know: that ESX checks every 20ms to migrate a vCPU to another pCPU for the optimal workload balance. This is configurable (0ms - 5000ms) in Cpu.MigratePeriod in Advanced Settings of you ESX server.