C952- chapter 2
Computer A requires 10 seconds to compress a file. Computer B requires 5 seconds. Which computer has higher execution time?
A: A's 10 sec is higher than B's 5 sec.
A program that translates a symbolic version of instructions into the binary version.
Assembler
Performs computations
Datapath: The datapath is where data is transformed via computations like addition or subtraction. Control and datapath are commonly together and called a processor.
A drummer's stick breaks, but he quickly grabs another one and continues playing the song.
Dependability via Redundancy: Having extras/backups is a good idea in many scenarios.
the number of tasks completed per unit time.
Throughput: Also called bandwidth
The percentage of good dies from the total number of dies on the wafer.
Yield
Response time is synonymous with
execution time
A nonvolatile semiconductor memory. It is cheaper and slower than DRAM but more expensive per bit and faster than magnetic disks.
flash memory
with the fastest, smallest, and most expensive memory per bit at the top of the hierarchy and the slowest, largest, and cheapest per bit at the bottom
hierarchy of memories
An advantage of a high-level language is enabling a programmer to
implement a program in less time
Execution time is directly proportional to
instruction count
The storage area in which programs are kept when they are running and that contains the data needed by the running programs
memory
As computing systems move to multicore microprocessors, programmers _____ to obtain performance benefits.
need to rewrite their programs
Reads data from memory. Ex: Display.
output
After the patterned wafer is chopped up into dies, the dies are
packaged
Parallel programming seeks to improve program _____.
performance
10^15 bytes is a _____byte.
peta
Memory layer used to store programs and data between runs
secondary memory
refer to elapsed time on an unloaded system
system performance
tasks completed per unit time EX. one clean car per minute
throughput
the measure of computer performance: the computer that performs the same amount of work in the least time is the fastest
time
Integrated circuits consist of_______ NOT vacuum tubes.
transistors
Blank wafers undergo 20 to 40 chemical processing steps to create
transistors, conductors, and insulators
dies per wafer =
wafer area/die area
These terms mean the total time to complete a task, including disk accesses, memory accesses, input/output (I/O) activities, operating system overhead—everything.
wall clock time, response time, or elapsed time
Parallelism achieved by performing the same operation on independent data
Data-level parallelism
The component of the processor that performs arithmetic operations.
Datapath
by including redundant components that can take over when a failure occurs and to help detect failures
dependable
Cars drive 60 km/h over a 1 km long bridge. A car thus requires 1 minute to cross the bridge. Cars stay separated by about 100 m, so 1 car enters and another exits the bridge every 6 seconds. The execution time is _________
1 minute: The time to complete one task (one car crossing the bridge) is 1 minute.
Power =
1/2 Capacity Load Voltage^2 * Frequency switched
The _____ Intel processor consumed the most power.
2004
The A5 package has a chip containing ____ ARM processors
2: 2 identical ARM processors are on the chip. The trend is to put more and more processors on a chip.
Multicore microprocessor
A microprocessor containing multiple processors ("cores") in a single integrated circuit.
ProcessorA has 75% of the capacitive load of processorB. ProcessorA also has a 20% voltage reduction and 10% shrink in frequency. What is the relative impact on dynamic power? A: 0.75×0.802×0.90=0.432 B: 0.75×0.202×0.10=0.003 C: 0.75×0.802×0.90=0.432V
A:Processor A uses 43.2% less power than processor B.
The user portion of the instruction set plus the operating system interfaces used by application programmers.
ABI-Application binary interface: It defines a standard for binary portability across computers
Behind a car's simple items like steering wheel, gas pedal, and brake pedal are complex mechanical/computerized details. Those simple items represent _____.
Abstraction
A rule stating that the performance enhancement possible with a given improvement is limited by the amount that the improved feature is used
Amdahl's Law
is an LCD that uses a transistor to control whether light passes for each pixel.
An active matrix display
Computer A requires 10 seconds to compress a file. Computer B requires 5 seconds. Which computer has higher performance?
B: Performance is defined such that bigger is better. Since B is faster than A, B has higher performance.
A given application written in Java runs 15 seconds on a desktop processor. A new Java compiler is released that requires only 0.6 as many instructions as the old compiler. Unfortunately, it increases the CPI by 1.1.Q:How fast can we expect the application to run using this new compiler? A: 15×0.61.1=8.2sec B: 15×0.6×1.1=9.9sec C: 15×1.10.6=27.5sec
B:The new compiler decreases the number of instructions by 0.6 and increases the number of clock cycles per instruction by 1.1.
program fragment
CPI
Large memory where most data is stored.
DRAM
Instruction Count CPI Clock cycle time =
CPU Time
Cpu execution time for a program (Normal) =
CPU clock cycles for a program * Clock cycle time
CPU execution time for a program (inversely) =
CPU clock cycles for a program/clock rate
The actual time the CPU spends computing for a specific task.
CPU execution time: Also called CPU time
The time for one clock period, usually of the processor clock, which runs at a constant rate
Clock cycle
The length of each clock cycle
Clock period
is the inverse of the clock period
Clock rate
The component of the processor that commands the datapath, memory, and I/O devices according to the instructions of the program.
Control
Sends signals that determine the operation of the other components.
Control: Control and datapath are commonly together and called a processor.
is designed for local communication among computers, usually within a single building.
Ethernet
A multicore microprocessor is a single processor capable of switching between multiple programs.
False
The following could be an assembly language instruction: 1000110010100000.
False:An assembly language instruction uses symbols that are more understandable to humans, such as: ADD A,B.
Supervisors are expensive, so less-capable but cheaper agents are placed closer to the customer describes what?
Hierarchy of Memories
Hardware that obeys the architecture abstraction
Implementation
Adding additional processors to a system that uses multiple processors for separate tasks -- for example, searching the web -- has what effect? Assume that before adding processors, tasks do not wait to execute (tasks do not "queue up").
Increases Throughput: More tasks can be completed per unit time, because the additional processor can execute additional tasks.
Writes data to memory. Ex: Keyboard.
Input
CPU time = (Inverse)
Instruction count * CPI/clock rate
CPU clock cycles =
Instructions for a program * Average clock cycles per instruction
either passes or blocks light.
LCD-liquid crystal display
Instruction count / execution time * 10^6
MIPS
A college student rents an apartment closer to campus than to her favorite weekend beach spot
Make the Common Case Fast: The student goes to campus more frequently than the beach, so she optimizes her commute for the common case.
Looking ahead is common in this law
Moore's Law
Software that manages hardware resources on behalf of other programs.
Operating system
Supervising program that manages the resources of a computer for the benefit of the programs that run on that computer.
Operating system
A sister is hanging clothes to dry. Her brother helps by hanging clothes simultaneously.
Performance via Parallelism: In this case, two people working in parallel can halve the task's 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.
Response time: Also called execution time
A faster memory technology than DRAM, but using more area to store a bit.
SRAM
Cache is built from
SRAM
Nonvolatile memory used to store programs and data between runs; typically consists of flash memory in PMDs and magnetic disks in servers.
Secondary memory
A substance that does not conduct electricity well
Semiconductor
Software that provides services that are commonly useful, including operating systems, compilers, loaders, and assemblers
Systems software
The collection of software on a computer that provides services to application software
Systems software
A house architect first designs a house with 5 rooms, then designs room details like closets, windows, and flooring.
Use Abstraction to Simplify Design: A "room" is a higher level abstraction important during early design. Later, the architect thinks of lower-levels details.
The CPU time spent in a program itself
User CPU time
Storage, such as DRAM, that retains data only if it is receiving power.
Volatile memory
fast will tend to enhance performance better than optimizing the rare case
common case
Execution time is the time required to
complete one task
cost per die =
cost per wafer/dies per wafer * yield
Adding additional processors to a system that uses multiple processors for separate tasks -- for example, searching the web -- has what effect? Assume that before adding processors, tasks often must wait to execute due to another task executing (tasks "queue up").
decreases response time AND increases throughput
Replacing a processor in a computer with a faster processor has what effect?
decreases response time AND increases throughput