CO1 WEEK 5 FACTORS AFFECTING PERFORMANCE OF CPU

Question 1

What affects CPU performance?

Answer 1

Clock speed
- N of cores
- Cache size
- RAM size
- WORD size
- Bus width

Question 2

What are Cores?

Answer 2

more cores usually faster processing - Higher complexity Improves performance tacks spit between cores

Question 3

What is parallel processing?

Answer 3

More than one processor =synchronised

Question 4

What is a Cache?

Answer 4

small amount of memory which is part of CPU = holds instructions which likely to be reused
- checks this before requesting data from RAM
- saves fetching

Question 5

What are the different grades of cache?

Answer 5

L1 part of the CPU itself both being the smallest but fastest to access.
Each level the cache gets larger but slower to access.
More L2 and L3 memory available the faster the computer can run.

Question 6

What is ROM?

Answer 6

ROM - Non volatile - store a limited n of instructions - not changeable

Question 7

What is memory ?

Answer 7

Memory - stores data and instruction

Question 8

What is RAM?

Answer 8

Random Access Memory is used to temp store data and instruction being used by the current program running.
The phrase ‘Random’ means that data and instruction can be read from or written to any part of the memory.

Question 9

What is word size?

Answer 9

• word = number of bits which moves from one component to another
• can only reference memory locations which fit within size of address bus
• how many bits CPU can manipulate in one go

Question 10

What is the Data Bus?

Answer 10

The amount of bits that can be transferred simultaneously from one device to another.
Provides two way connection allowing data and instructions to travel on.

Question 11

What is the Address bus?

Answer 11

access data in memory one direction from CPU
- address bus determines maximum amount of accessible locations

Question 12

What are the names of the buses?

Answer 12

Address bus
- Data bus
- Control bus

Question 13

What is the Control Bus?

Answer 13

two way to transmit commands,timing,specific status info

Question 14

What is clock speed and how does it relate to a computers performance?

Answer 14

CPU is a sequential machine so carries one instruction at a time in order.
To coordinate this it has a internal clock which runs at certain speeds which indicates how fast a CPU can run.

Question 15

What is clock speed measured in and what does it indicate?

Answer 15

Measured in megahertz (MHz) or gigahertz (GHz) and corresponds to how many instruction cycles the CPU can deal with in a second.
(A 4 GHz CPU performs four billion cycles a second.)

Question 16

What is overclocking?

Answer 16

Where some people increase CPU clock speed to try to make their computer run faster.
Possible to change max CPU clock speed in BIOS settings.

Question 17

What are the ways cores can improve performance of a computer?

Answer 17

Parallel Processing where a task or problem is split up across all the available cores so each core tackle part of the overall problem. (In theory doubles or quadruples performance.)
Multitasking where multiple tasks can be performed at the same time
e.g. each core handles a seperate piece of software.

Question 18

Does increasing number of cores increase performance?

Answer 18

Doubling number of cores doesn’t necessarily double computer speed as this extra speed is used up when they communicate between each other.

Question 19

How does more RAM increase computer performance?

Answer 19

More instructions/programs held in RAM and run at same time.
Software responds faster.
Can run more memory intensive software.
Reduces use of Virtual memory.
Less use of Hard Disk which slower to access.