Chapter 1 Flashcards
Desktop computer
A computer designed for use by an individual, usually incorporating a graphics display, a keyboard, and a mouse
Server
A computer used for running larger programs for multiple users, often simultaneously, and typically accessed only via a network
Supercomputer
A class of computers with the highest performance and cost; they are configured as servers and typically cost millions of dollars
Terabyte
Originally 2^40 bytes, although some communications and secondary storage systems have redefined it to mean 10^12 bytes
Petabyte
Depending on the situation, either 1000 or 1024 terabytes
Datacenter
A room or building designed to handle the power, cooling, and networking needs of a large number of servers
Embedded computer
A computer inside another device used for running one predetermined application or collection of software
Multicore microprocessor
A microprocessor containing multiple processors (“cores”) in a single integrated circuit
Acronym
A word constructed by taking the initial letters or a string of words. For example: RAM is an acronym for Random Access Memory, and CPU is an acronym for Central Processing Unit
Systems software
Software that provides services that are commonly useful, including operating systems, compilers, loaders, and assemblers.
Operating system
Supervising program that manages the resources of a computer for the benefit of the programs that run on that computer
Compiler
A program that translates high-level language statements into assembly language statements
Binary digit
Also called a bit. One of the two numbers in base 2 (0 or 1) that are the components of information
Instruction
A command that computer hardware understands and obeys
Assembler
A program that translates a symbolic version of instructions into the binary version
Assembly language
A symbolic representation of machine instructions
Machine language
A binary representation of machine instructions
High-level programming language
A portable language such as C, C++, Java, or Visual Basic that is composed of words and algebraic notation that can be translated by a compiler into assembly language
Input device
A mechanism through which the computer is fed information, such as the keyboard or mouse
Output device
A mechanism that conveys the result of a computation to a user or another computer
Liquid crystal display
A display technology using a thin layer of liquid polymers that can be used to transmit or block light according to whether a charge is applied
Active matrix display
A liquid crystal display using a transistor to control the transmission of light at each individual pixel
Pixel
The smallest individual picture element. Screens are composed of hundreds of thousands to millions of pixels, organized in a matrix
Motherboard
A plastic board containing packages of integrated circuits or chips, including processor, cache, memory, and connectors for I/O devices such as networks and disks
Integrated circuit
Also called a chip. A device combining dozens to millions of transistors
Memory
The storage area in which programs are kept when they are running and that contains the data needed by the running programs
Dynamic random access memory (DRAM)
Memory built as an integrated circuit; it provides random access to any location
Dual inline memory module (DIMM)
A small board that contains DRAM chips on both sides. (SIMMs have DRAMs on only one side)
Central processor unit (CPU)
Also called processor. The active part of the computer, which contains the datapath and control and which adds numbers, tests numbers, signals I/O devices to activate, and so on
Datapath
The component of the processor that performs arithmetic operations
Control
The component of the processor that commands the datapath, memory, and I/O devices according to the instructions of the program
Cache memory
A small, fast memory that acts as a buffer for a slower, larger memory
Static random access memory (SRAM)
Also memory built as an integrated circuit, but faster and less dense that DRAM
Abstraction
A model that renders lower-level details of computer systems temporarily invisible to facilitate design of sophisticated systems
Instruction set architecture
Also called architecture. An abstract interface between the hardware and the lowest-level software that encompasses all the information necessary to write a machine language program that will run correctly, including instructions, registers, memory access, I/O, …
Application binary interface (ABI)
The user portion of the instruction set plus the operating system interfaces used by application programmers. Defines a standard for binary portability across computers
Implementation
Hardware that obeys the architecture abstraction
Volatile memory
Storage, such as DRAM, that reains data only if it is receiving power
Nonvolatile memory
A form of memory that retains data even in the absence of a power source and that is used to store programs between runs. Magnetic disk is nonvolatile.
Main memory
Also called primary memory. Memory used to hold programs while they are running; typically consists of DRAM in today’s computers
Secondary memory
Nonvolatile memory used to store programs and data between runs; typically consists of magnetic disks in today’s computers
Magnetic disk
Also called hard disk. A form of nonvolatile secondary memory composed of rotating platters coated with a magnetic recording material
Flash memory
A nonvolatile semiconductor memory. It is cheaper and slower than DRAM but more expensive and faster than magnetic disks
Gigabyte
Traditionally 2^30 bytes, although some communicaions and secondary storage systems have redefined it to mean 10^9 bytes. Similarly, depending on the context, megabyte is either 2^20 or 10^6
Local area network (LAN)
A network designed to carry data within a geographically confined area, typically within a single building
Wide area network (WAN)
A network extended over hundreds of kilometers that can span a continent
Vacuum tube
An electronic component, predecessor of the transistor, that consists of a hollow glass tube about 5 to 10 cm long from which as much air has been removed as possible and that uses an electron beam to transfer data
Transistor
An on/off switch controlled by an electric signal
Very large-scale integrated (VLSI) circuit
A device containing hundreds of thousands to millions of transistors
Response time
Also called 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
Throughput
Also called bandwidth. Another measure of performance it is the number of tasks completed per unit time
CPU execution time
Also called CPU time. The actual time the CPU spends computing for a specific task
User CPU time
The CPU time spent in a program itself
System CPU time
The CPU time spent in the operating system performing tasks on behalf of the program
Clock cycle
Also called tick, clock tick, clock period, clock, cycle. The time for one clock period, usually of the processor clock, which runs at a constant rate
Clock period
The length of each clock cycle
Clock cycles per instruction (CPI)
Average number of clock cycles per instruction for a program or program fragment
Instruction count
The number of instructions executed by the program
Instruction mix
A measure of the dynamic frequency of instructions across one or many programs
Silicon
A natural element that is a semiconductor
Semiconductor
A substance that does not conduct electricity well
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
Wafer
A slice from a silicon ingot no more that 0.1 inch thick, used to create chips
Defect
A microscopic flaw in a wafer or in patterning steps that can result in the failure of the die containing that defect
Die
The individual rectangular sections that are cut from a wafer, more informally known as chips
Yield
The percentage of good dies from the total number of dies on the wafer
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
Benchmark
A program selected for use in comparing computer performance
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
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 execution time and 10^6
