CPU Share Versus Utilization
Share allocation is not the same as utilization. A project that is
allocated 50 percent of the CPU resources might average only a 20 percent
CPU use. Moreover, shares serve to limit CPU usage only when there is
competition from other projects. Regardless of how low a project's allocation is, it
always receives 100 percent of the processing power if it is running alone
on the system. Available CPU cycles are never wasted. They are distributed between
projects.
The allocation of a small share to a busy workload might slow
its performance. However, the workload is not prevented from completing its work if
the system is not overloaded.