The great people over at VRC coined the term “Red Bull Setting” when they showed how to increase your VDI throughput.
The jest of the Red Bull setting is:
• Physically CPU has to over 50%
• Your CPU has to have Hyper-threading
• You can see a 20% increase with HaltingIdleMsecPenaltyMax set to 2000 or you can disable it.
• To ensure a VM gets it fair share of time, ESX will not let anything run on the one side of the core by disabling it while the vm takes its turn.
That is pretty high level overview but for more info go check out their sight. I noticed in vSphere 5 that I think the setting has changed its name. The picture below is the old setting disabled. The one after that is what appears to be the new one. When I upgrade my test environment I will double check to see if the setting is kept.
Old Setting: HaltingIdleMsecPenaltyMax