Windows System Resource Manager cannot prevent an application from using CPU bandwidth. The Windows System Resource Manager service continually monitors the CPU usage of a process. If the CPU usage of a process exceeds the target defined in the resource-allocation policy, and the process begins to consume extra CPU bandwidth, the dynamic process priority management algorithm takes effect. Windows System Resource Manager lowers or raises the priority of the process and other running processes in order to find a process that can consume the extra CPU bandwidth. This brings the CPU usage of the process back down to its target.

Typically, CPU consumption targets are more likely to be met if other running processes are able to consume CPU bandwidth. This reduces the amount of unused CPU bandwidth that is available.

There is no mechanism to ensure that the CPU usage of a process will match its target. Nor is there a way to ensure that the unused bandwidth will be consumed by other processes if re-allocation occurs.

In addition, if no other processes are able to consume the unused CPU bandwidth, there is nothing to prevent the original managed process from consuming the unused bandwidth and exceeding its target allocation. On systems with under-utilized CPU bandwidth, the actual bandwidth usage will not be close to its target values because Windows System Resource Manager cannot prevent processes from consuming the unused bandwidth.