Each device controller has its own local buffer.

The statement that each device controller has its own local buffer is false. In operating systems, device controllers do manage input and output operations and often utilize buffers, but not every device controller has its own local buffer. Instead, devices may share memory buffers managed by the operating system. Buffers are used to temporarily hold data during I/O operations, aiding in efficient data transfer and allowing devices to operate at different speeds without causing delays.

For instance, when data is being written to a disk, the operating system might use a system-wide buffer in main memory to manage the data flow between the application and the disk drive instead of relying solely on a buffer that's local to the device controller. This centralized buffering approach can simplify management and improve performance by coordinating between multiple devices and system resources.