System and Method of Dynamically Switching Queue Threshold

A system and method of dynamically switching the threshold of a data queue, such as FIFO, is disclosed. The data queue has a first threshold and a second threshold, wherein the first threshold is greater than the second threshold. The data queue is dynamically switched between the first threshold and the second threshold according to different power state of a central processing unit (CPU). A system memory is requested to fill the data queue with data whenever amount of the data queue is less than the switched first/second threshold.