Different devices compete for processor time, and they do so by sending a signal to the CPU to interrupt the current process. It is important that you detect when a device is using an excessive number of interrupts.
http://support.microsoft.com/default.aspx/kb/167050You can monitor the number of interrupts per second and identify a device that is using a high number. For example, you can create a situation using the Interrupts/Sec attribute, with the threshold set to a specific limit. This situation triggers an alert when the device interrupts are three thousand per second or higher.