Question

求懂英语的大神帮我做一下下面这些有关计算机硬件的题T.T

1. On computer 1, all instructions take 10 nsec to execute. On computer 2, they all take 5
nsec to execute. Can you say for certain that computer 2 is faster? Discuss.

2. As one goes down the five-level memory hierarchy, the access time increases. Make a
reasonable guess about the ratio of the access time of optical disk to that of register
memory. Assume that the disk is already online.

3. Compute the data rate of the human ear from the following information. People can hear
frequencies up to 22 kHz. To capture all the information in a sound signal at 22 kHz, it is
necessary to sample the sound at twice that frequency, that is, at 44 kHz. A 16-bit sample
is probably enough to capture most of the auditory information (i.e., the ear cannot
distinguish more than 65,535 intensity levels).

4. A disk has 4096 bits/sector, 1024 sectors/track and a rotation rate of 7200 RPM. What is
the sustained transfer rate of the disk over one track?

5. Imagine you are writing the disk-management part of an operating system. Logically,
you represent the disk as a sequence of blocks, from 0 on the inside to some maximum on
the outside. As files are created, you have to allocate free sectors. You could do it from
the outside in or the inside out. Does it matter which strategy you choose on a modern
disk? Explain your answer.

6. How long does it take to read a disk with 10,000 cylinders, each containing four tracks of
2048 sectors? First, all the sectors of track 0 are to be read starting at sector 0, then all
the sectors of track 1 starting at sector 0, and so on. The rotation time is 10 msec, and a
seek takes 1 msec between adjacent cylinders and 20 msec for the worst case. Switching
between tracks of a cylinder can be done instantaneously.

7. To be able to fit 133 minutes worth of video on a single-sided single-layer DVD, a fair
amount of compression is required. Calculate the compression factor required. Assume
that 3.5 GB of space is available for the video track, that the image resolution is 720 x
480 pixels with 24-bit color (RGB at 8 bits each), and images are displayed at 30
frames/sec.

Answer 1

1。计算机1,所有指令需要10 nsec执行。电脑2,他们都用5
nsec执行。你能确定计算机2快?讨论。

2。正如一位下降5级内存层次结构,访问时间也在不断增加。做一个
合理的猜测的比值光盘的寄存器的访问时间
内存。假设磁盘已经在线。

3所示。计算的数据率人耳从以下信息。人们可以听到
22 kHz频率。捕获的所有信息在22 kHz,声音信号
必要样本频率的声音的两倍,也就是说,在44千赫。一个16位的样本
可能是足以捕获大部分听觉信息(即。,耳朵不能
区分两种强度超过65535)。

4所示。一个磁盘有4096位/部门,1024部门/跟踪和转速为7200 RPM。是什么
磁盘的持续传输率跟踪?

5。假设您正在编写一个操作系统的磁盘管理部分。从逻辑上讲,
你代表的磁盘作为一个序列块,从0内部一些最大
外面的。文件被创建,你必须分配免费的行业。你可以这样做
在外面或里面。它不管你选择哪个策略在现代吗
磁盘吗?解释你的答案。

6。花多长时间阅读一个磁盘10000缸,每个包含四个跟踪的
2048部门?首先,所有的行业跟踪要读从部门0 0,然后
跟踪1的行业部门0开始,等等。旋转时间是10毫秒,
寻找需要1毫秒之间相邻气缸为最坏的情况下和20毫秒。切换
轨道之间的气缸可以瞬间完成。

7所示。能够适应价值133分钟的视频在一个单面单层DVD,公平
所需的压缩。计算所需的压缩因子。假设
3.5 GB的可用空间的视频跟踪,图像分辨率720 x
480像素与24位颜色在每8位(RGB),在30和图像显示
帧/秒。