Q: There is a system with 4 flash memory banks. When data comes to the system, it will randomly send it to one of the 4 banks. The system has a feature called Native Command Queuing (NCQ) which allows the host to send multiple commands at a time.
The number of commands sent at a time is called the queue depth. With a queue depth of 1, only 1 of 4 memory banks will be active.
With a queue depth of 2, we expect 2 of 4 flash memory banks to be active except in the case when both commands are to the same bank.
The question is, what is the expected number of flash memory banks that would be active, given queue depths of:
2, 4, 8, and 16 ?
At first I didn't see a trick in the question