Ch 2.5 - 2.10

Question 1

“What is a transistor?”

Answer 1

“An on/off switch controlled by an electric signal.”

Question 2

“What is a very large-scale integrated (VLSI) circuit?”

Answer 2

“A device containing hundreds of thousands to millions of transistors.”

Question 3

“What is silicon?”

Answer 3

“A natural element that is a semiconductor.”

Question 4

“What is a semiconductor?”

Answer 4

“A substance that does not conduct electricity well.”

Question 5

“What is a silicon crystal ingot?”

Answer 5

“A rod composed of a silicon crystal that is between 8 and 12 inches in diameter and about 12 to 24 inches long.”

Question 6

“What is a wafer?”

Answer 6

“A slice from a silicon ingot no more than 0.1 inches thick, used to create chips.”

Question 7

“What is a defect?”

Answer 7

“A microscopic flaw in a wafer or in patterning steps that can result in the failure of the die containing that defect.”

Question 8

“What is a die (chip)?”

Answer 8

“The individual rectangular sections that are cut from a wafer, more informally known as chips.”

Question 9

“What is yield?”

Answer 9

“The percentage of good dies from the total number of dies on the wafer.”

Question 10

“What is response time (execution time)?”

Answer 10

“The total time required for the computer to complete a task, including disk accesses, memory accesses, I/O activities, operating system overhead, CPU execution time, and so on.”

Question 11

“What is throughput (bandwidth)?”

Answer 11

“Another measure of performance, it is the number of tasks completed per unit time.”

Question 12

“What is wall clock time (response time/elapsed time)?”

Answer 12

“The total time to complete a task, including disk accesses, memory accesses, input/output (I/O) activities, operating system overhead—everything.”

Question 13

“What is CPU execution time (CPU time)?”

Answer 13

“The actual time the CPU spends computing for a specific task.”

Question 14

“What is user CPU time?”

Answer 14

“The CPU time spent in a program itself.”

Question 15

“What is system CPU time?”

Answer 15

“The CPU time spent in the operating system performing tasks on behalf of the program.”

Question 16

“What is system performance (CPU performance)?”

Answer 16

“System performance refers to elapsed time on an unloaded system and CPU performance refers to user CPU time.”

Question 17

“What is clock rate?”

Answer 17

“The inverse of the clock period.”

Question 18

“What is a clock cycle (tick/clock tick/clock period/clock/cycle)?”

Answer 18

“The time for one clock period, usually of the processor clock, which runs at a constant rate.”

Question 19

“What is clock period?”

Answer 19

“The length of each clock cycle.”

Question 20

“What is clock cycles per instruction (CPI)?”

Answer 20

“Average number of clock cycles per instruction for a program or program fragment.”

Question 21

“What is instruction count?”

Answer 21

“The number of instructions executed by the program.”

Question 22

“What is instruction mix?”

Answer 22

“A measure of the dynamic frequency of instructions across one or many programs.”

Question 23

“What is IPC (instructions per clock cycle)?”

Answer 23

“Some designers invert CPI to talk about IPC, or instructions per clock cycle. If a processor executes on average two instructions per clock cycle, then it has an IPC of 2 and hence a CPI of 0.5.”

Question 24

“What is fanout?”

Answer 24

“The number of transistors connected to an output (called the fanout).”

Question 25

“What are Redundant Arrays of Inexpensive Disks (RAID)?”

Answer 25

“Many disks in conjunction can offer much higher throughput, which was the original inspiration of Redundant Arrays of Inexpensive Disks (RAID).”

Question 26

“What is a graphics processing unit (GPU)?”

Answer 26

“The graphics processing unit (GPU) is a hardware component that accelerates graphics.”

Question 27

“What is a workload?”

Answer 27

“A set of programs run on a computer that is either the actual collection of applications run by a user or constructed from real programs to approximate such a mix. A typical workload specifies both the programs and the relative frequencies.”

Question 28

“What is a benchmark?”

Answer 28

“A program selected for use in comparing computer performance.”

Question 29

“What is SPEC (System Performance Evaluation Cooperative)?”

Answer 29

“SPEC (System Performance Evaluation Cooperative) is an effort funded and supported by a number of computer vendors to create standard sets of benchmarks for modern computer systems.”

Question 30

“What is SPECratio?”

Answer 30

“Dividing the execution time of a reference processor by the execution time of the evaluated computer normalizes the execution time measurements; this normalization yields a measure, called the SPECratio, which has the advantage that bigger numeric results indicate faster performance.”

Question 31

“What is Amdahl’s Law?”

Answer 31

“A rule stating that the performance enhancement possible with a given improvement is limited by the amount that the improved feature is used. It is a quantitative version of the law of diminishing returns.”

Question 32

“What is million instructions per second (MIPS)?”

Answer 32

“A measurement of program execution speed based on the number of millions of instructions. MIPS is computed as the instruction count divided by the product of the execution time and 10^6.”

Question 33

“What is a transistor?”

Answer 33

“An on/off switch controlled by an electric signal.”