This homework consists of the following problems. All problems cover material from the textbook chapters 7, 8, and 12.
- Calculate the overall speedup of a system that spends 65% of its time in calculations with a processor upgrade that provides for 125% greater throughput.
- Suppose your company has decided that it wants to make certain servers faster. Processes in the workload spend 60% of their time using the CPU and 40% on I/O. In order to achieve an overall system speedup of 25%:
- How much faster does the CPU need to be?
- How much faster does the disk need to be?
- Suppose the daytime processing load consists of 70% CPU activity and 30% disk activity. Your customers are complaining that the system is slow. After doing some research, you have learned that you can upgrade your disks for $1,500 to make them 2.75 times as fast as they are currently. You have also learned that you can upgrade your CPU to make it 1.5 as fast for $2,000.
- Which would you choose to yield the best performance improvement for the least amount of money?
- Which option (the CPU or the disk) would you choose if you don’t care about the money, but want a faster system?
- What is the break-even point for the upgrades? That is, what price would we need to charge for the CPU (or the disk – change only one) so the result was the same cost per 1% increase for both?
- Name four types of I/O architectures. Where are each of these typically used and why are they used there?
- a) Which of the RAID systems described in this chapter cannot tolerate a single disk failure?
- b) Which can tolerate more than one simultaneous disk failure?
- a) What is the difference between multiprogramming and multiprocessing?
- b) What is the difference between multiprogramming and multithreading?
- Why is the execution environment of a Java class called a virtual machine? How does this virtual machine compare to a real machine running code written in C?
- We stated that the performance of a Java program running in the JVM cannot possibly match that of a regular compiled language. Explain why this is so.
- Into which class of networks do the following IP addresses fall?
- 230.7.1
- 17.44.39
- 255.255.255
- Scavenger Hunt: In your own words, write a short paragraph to answer the following: Who is Vinton Cerf and why/when did he win the ACM Turing Award?




