A Dataflow displays the current level of activity. As the rate of data transfer increases, so too does the speed of the flow. If the statistic that the flow represents moves to another threshold, the flow may change color. The combination of movement and color makes it easy to spot congested areas. A graph above the flow shows how the load has varied over time.
Reading or writing data requires a disk to access the disk sector where the requested data resides. After this sector is accessed, the amount of time required for a disk to read or write data from or to storage media is referred to as disk transfer time.
Transfer time, usually expressed in milliseconds, is part of the disk access time, that is, the total time required for the computer to process the data request from the processor and then retrieve the needed data from a storage device.