D.5 Performance Loss When Using Multiple Virtual CPUs

In a virtual machine that is configured with multiple virtual CPUs, in certain circumstances (for example, when there is a lot of synchronization between threads), performance might be affected.

In the current release, Oracle recommends that you configure a single virtual CPU. Avoid configuring the virtual machine with more CPUs than are essential for the application, because each extra CPU causes additional overhead, with the largest increase in overhead occurring when moving from one CPU to two CPUs.