申論題

4. (8%) Assume the system workload consists of repeated reads of 64KB block at random disk locations. For the following system setup, (A) what is the IOPS (I/Os per second) for CPU, memory bus, and disk drive,respectively? (B) what (CPU, memory bus, or disk) is the bottleneck in the system?

●The user program uses 2 million cycles to process each I/O operation.
●The operating system requires 1 million cycles of overhead for each I/O operation.
●The clock rate is 3GHz.
●The maximum sustained transfer rate of the memory bus is 640MB/sec
●One disk drive which rotates at 7200RPM, has an average seek time of 8ms, and has a transfer rate of 64MB/sec. The disk controller overhead is 2ms.
Express your answer as the following table