Computer Systems and Performance

Question 1

Key goal of computer designers

Good performance in the sense of ______

Answer 1

execution speed

Question 2

The benefit of increasing speed

Answer 2

Not to do some things faster, but that new applications become possible

Question 3

Increases in processor speed have been achieved by

Answer 3

improvements in implementation technology(VLSI) and development of clever processor organizations and architecture
reducing power consumption

Question 4

reduce power consumption in order to

Answer 4

avoid overheating of chips with many transistors
proliferation of battery powered devices
energy cost in datacenters
climate change

Question 5

to understand computer organization/architecture

Answer 5

we need to understand what the hardware actually does (machine language executed)

Question 6

assembly language is a ________ ________ of machine language

Answer 6

symbolic/textual representation

Question 7

A Processor consists of

Answer 7

the datapath

the control

Question 8

the datapath

Answer 8

carries out the operations specified in the machine language instructions being executed

Question 9

the control

Answer 9

tells the datapath (and memory and I/O devices) what to do

Question 10

in reality, the execution of each instruction is ________

the goal is to ______

Answer 10

typically overlapped with the executions of other instructions
increase execution speed, and maintain the same outcome as if execution was strictly sequential

Question 11

memory

Answer 11

processor caching

and virtual memory

Question 12

memory hierarchy managed so as to achieve

Answer 12

high speed and high capacity

Question 13

Why I should know assembly language

Answer 13

• know about how computers work
• important when programming systems software
• important when application performance needs to be optimized (exploit parralellism and/or caching)

Question 14

CPU execution time as a product of 3 factors

Answer 14

instruction count
clock cycle time
CPI

Question 15

Instruction count

Answer 15

of machine language instructions executed

Question 16

Instruction count depends on

Answer 16

high level language program
Instruction set program
compiler

Question 17

processors rely on ______ to time their operations

Answer 17

clock cycle time

Question 18

the clock cycle time is

Answer 18

the time between clock ticks

Question 19

each step of instruction execution requires

Answer 19

one clock cycle

Question 20

clock cycle time is commonly measuredn

Answer 20

nano seconds or pico seconds

Question 21

cct depends on

Answer 21

architecture implementation

Question 22

may need to derive cct from ______ using ____

Answer 22

clock rate

cct = 1/clock rate

Question 23

clock rate is commonly measured in

Answer 23

GHz (billions of cycles per second)

Question 24

processors can dynamically vary their clock rate to ___

for such processors it is the _______ that is a factor in the CPU execution time

Answer 24

achieve some desired trade off between power usage and performance
average clock cycle time when running a program

Question 25

CPI depends on

Answer 25

architecture implementation
high level language program
compiler
ISA

Question 26

CPU execution time =

Answer 26

instruction count * clock cycle time * cpi

Question 27

Finish Jan 8 flash cards

Answer 27

and Jan 10