Ch 2.5 - 2.10 Flashcards
“What is a transistor?”
“An on/off switch controlled by an electric signal.”
“What is a very large-scale integrated (VLSI) circuit?”
“A device containing hundreds of thousands to millions of transistors.”
“What is silicon?”
“A natural element that is a semiconductor.”
“What is a semiconductor?”
“A substance that does not conduct electricity well.”
“What is a silicon crystal ingot?”
“A rod composed of a silicon crystal that is between 8 and 12 inches in diameter and about 12 to 24 inches long.”
“What is a wafer?”
“A slice from a silicon ingot no more than 0.1 inches thick, used to create chips.”
“What is a defect?”
“A microscopic flaw in a wafer or in patterning steps that can result in the failure of the die containing that defect.”
“What is a die (chip)?”
“The individual rectangular sections that are cut from a wafer, more informally known as chips.”
“What is yield?”
“The percentage of good dies from the total number of dies on the wafer.”
“What is response time (execution time)?”
“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.”
“What is throughput (bandwidth)?”
“Another measure of performance, it is the number of tasks completed per unit time.”
“What is wall clock time (response time/elapsed time)?”
“The total time to complete a task, including disk accesses, memory accesses, input/output (I/O) activities, operating system overhead—everything.”
“What is CPU execution time (CPU time)?”
“The actual time the CPU spends computing for a specific task.”
“What is user CPU time?”
“The CPU time spent in a program itself.”
“What is system CPU time?”
“The CPU time spent in the operating system performing tasks on behalf of the program.”
“What is system performance (CPU performance)?”
“System performance refers to elapsed time on an unloaded system and CPU performance refers to user CPU time.”
“What is clock rate?”
“The inverse of the clock period.”
“What is a clock cycle (tick/clock tick/clock period/clock/cycle)?”
“The time for one clock period, usually of the processor clock, which runs at a constant rate.”
“What is clock period?”
“The length of each clock cycle.”
“What is clock cycles per instruction (CPI)?”
“Average number of clock cycles per instruction for a program or program fragment.”
“What is instruction count?”
“The number of instructions executed by the program.”
“What is instruction mix?”
“A measure of the dynamic frequency of instructions across one or many programs.”
“What is IPC (instructions per clock cycle)?”
“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.”
“What is fanout?”
“The number of transistors connected to an output (called the fanout).”
“What are Redundant Arrays of Inexpensive Disks (RAID)?”
“Many disks in conjunction can offer much higher throughput, which was the original inspiration of Redundant Arrays of Inexpensive Disks (RAID).”
“What is a graphics processing unit (GPU)?”
“The graphics processing unit (GPU) is a hardware component that accelerates graphics.”
“What is a workload?”
“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.”
“What is a benchmark?”
“A program selected for use in comparing computer performance.”
“What is SPEC (System Performance Evaluation Cooperative)?”
“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.”
“What is SPECratio?”
“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.”
“What is Amdahl’s Law?”
“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.”
“What is million instructions per second (MIPS)?”
“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.”
“What is a transistor?”
“An on/off switch controlled by an electric signal.”
