Memory Problem.
Media applications that play audio or video files are part of a class of
workloads called "streaming" workloads; i.e , they bring in large amounts of
data but do not reuse much of it. Consider a video streaming workload that
access a 512KB working set sequentially with the following address stream:
0,4,8,12,16,20,24,28,32......
(1)Assume a 64KB direct-mapped cache with a 32-byte line. What is the miss
rate for the address stream above. How is this miss rate sensitive to the
size of the cache or the working set? How would you categorize the misses this
workload is experiencing, based on the 3C model.
(2)Recompute the miss rate when the cache line size is 16 byte , 64 bytes, and
128 bytes? What Kind of locality is this workload exploiting?
I/O Problem.
What is the bottleneck in the following system setup, the CPU , memory
bus, or the disk set?
1. The user program continuously performs reads of 64KB blocks, and requires
2 million cycles to process each block.
2. The operating system requires 1 million cycles of overhead for ezch I/O
oeration.
3. The clock rate is 3GHz.
4. The maximum sustained transfer rate of the memory bus is 640MB/sec.
5. The read/write bandwidth of the disk controller and the disk drives is
64MB/sec, disk average seek plus rotational latency is 9ms.
6. There are 20 disks attached to the bus each with its own controller.
(Assume that each disk can be controlled independently and ignore disk
conflicts.)
以上問題看張凡講義上的解答看不懂，麻煩請各位高手幫幫忙，在此先說聲謝謝^^
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