Performance Items

Question 1

What is CPU Frequency

Answer 1

cycles/second -
Clock rate- how many pauses are issues per second.
CPU cycle is the amount of time CPU preforms fetch, decode, excute.

Question 2

CPU clock device

Answer 2

a device (hardware) that emits synchronization pauses. When such signal arrives to CPU component, CPU component does one unit of work

Question 3

CPU Cycle

Answer 3

time between two synchronization pulses

Question 4

What is the measurement unit of CPU frequency? What exactly does it measure?

Answer 4

the frequency of synchronization pulses in the CPU. cycles per second.

Question 5

Does CPU frequency affect the computer performance?

Answer 5

The higher the frequency, the higher the computer performance. More instructions are done pers second.

Question 6

Name other factors that define computer performance

Answer 6

number of cores, CPU architecture, RAM performance, cache efficiency and speed

Question 7

What are the software factors that affect execution speed?

Answer 7

program efficiency, compiler efficiency

Question 8

What hurts program execution speed more: weak hardware or inefficient program code?

Answer 8

Inefficent Program Code

Question 9

What is the most reliable way to compare performance of different computers?

Answer 9

Benchmarks

Question 10

Benchmark Suites

Answer 10

fixed program that is used by different computers to compare computer performance.
Set of benchmarks to get a well-rounded performance effiency-Different benchmarks stress different components, like CPU, memory, and storage.

Question 11

Prefixes k, M, G, ki, Mi, Gi, p, n.

Answer 11

K = 1000 = 10^3
M = 1,000,000 = 10^6
G = 1,000,000,000 = 10^9

p(pico = 10^-12
n= 10^-9
micro = 10^-6
mili=10^3

KB = 2^10 = 1024
MB = 2^20= 1,000,000+
GB = 2^30

Question 12

How do you compare execution times of two programs?

Answer 12

no running time difference, only ratio

Question 13

Avergae CPI

Answer 13

average_CPI = total_number_of_cycles /dynamic_intsr_count

Question 14

What is dynamic instruction count? What is the measurement unit dynamic instruction count?

Answer 14

Actual number of instructions for CPU to finihs the whole program.

UNIT: Instruction:

Question 15

Equations that connect execution time, total number of cycles, CPU frequency (also known as clock rate), cycle duration, average CPI, dynamic instruction count.

Answer 15

LOOK AT NOTION

Question 16

Powerwall

Answer 16

powerwall is about the physical limitations that prevent engineers from raising CPU frequency

Question 17

Why do we want to raise CPU frequency

Answer 17

The higher the frequency, the higher the computer performance, but the more heat the CPU is generating

Question 18

What prevents engineers from raising CPU frequency?

Answer 18

more heat the CPU is generating. CPU stops functioning corrrectly.

Question 19

What are the advantages of using lower voltage?

Answer 19

lower heat generation
longer battery life
lower electricity bills

Question 20

Transistor

Answer 20

small CPU components

Question 21

What is transistor leakage?

Answer 21

transistor imperfection that doesn’t allow to use transistors with a very low voltage

Question 22

Formula for

Answer 22

CPU time = Total CPU clock cyles/clock rate (cycle/sec)

Question 23

CPI

Answer 23

Cycles per Instruction

Question 24

Total Cycles

Answer 24

Average
CPI (cylcer/instr) * instruction_Count