OCR J277 1.1.2 CPU Performance Factors

A CPU with four cores is called a [???]-core processor?

Answer explanation

Just like Math's, Quad relates to the number 4.

QUADrilateral = 4 Sided Shape.

QUADruple = Four times as much.

QUAD-core = 4 cores on the CPU.

Where would you store the most frequently used instructions?

• Registers

• Secondary Storage

• Cache

• Main Memory

Answer explanation

Cache is where we store any frequently used instructions during processing, because it's inside the CPU it is super quick to access them when needed.

Which of the following CPU's are quicker?

• 1.5GHz Quad-core Processor

• 4.5GHz Dual-core processor

• 2.2GHz Octa-core processor

• 2Ghz Hex-core processor

Answer explanation

It all comes down to a bit of simple maths, Take the clock speed, multiply it by the number of cores to get the maximum possible clockspeed.

In this case:

1.5 x 4 = 6GHz

4.5 x 2 = 9GHz

2.2 x 8 = 17.6GHz

2 x 6 = 12GHz

Cache memory has three levels, Which of them is the biggest?

• Level 1 (Internal Cache)

• Level 2 (Shared Cache, Inside the Core)

• Level 3 (Shared Cache, Outside the Core)

Answer explanation

Bigger means more space!, Level 3 needs to store frequently used instructions from ALL of the cores so it needs to be bigger than the rest.

Cache memory has three levels, Which of them is the quickest?

• Level 1 (Internal Cache)

• Level 2 (Shared Cache, Inside the Core)

• Level 3 (Shared Cache, Outside the Core)

Answer explanation

Bigger means more space, this means it takes longer to find the instruction it needs to run next.

The smaller the space, the quicker it is to search making Level 1 the quickest level.

A CPU is measured in Hertz, this speed is the maximum number of instructions which can be processed in a second. This speed is known as the [???]

Answer explanation

The clock speed is the number of instructions which can be executed per second measured in hertz (more commonly seen in GHz) if your CPU is 2.5GHz it means the CPU can execute a maximum of 2.5 billion instructions per second.

That is 3.5x more then you will blink in your entire life! (If you live up to 100)

Which of the following components are part of the CPU?

• Cache Memory

• RAM

• Control Unit

• Arithmetic Logic Unit

• ROM

Answer explanation

RAM (Random Access Memory) and ROM (Read Only Memory) are not part of the CPU.

Although RAM is used by the CPU to store instructions to use when running programs.

We will learn about them in the next unit!

What does CPU stand for?

• Central Processing Unit

• Central Purifying Unit

• Central Parallel Unit

• Central Positioned Unit

Inside the CPU, you will find:

• ALU, CU, registers, cache memory

• ADU, PC, storage, RAM memory

• ARM, PC, controller, cache memory

• APM, CU, time signal, RAM memory

The MAR stores the _______ of data which is either being sent to or fetched from the RAM.