SLR2 Flashcards
What is at the core of all computers
The instruction set, which is the set of instructions written in machine code that can be recognised by a CPU
What are the 2 types of processor
CISC & RISC
Main memory has 10 what
Location addresses named
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
What does the execution unit operate on
The data loaded into one of the 6 registers labelled
r000
r001
r010
r011
r100
r101
What does CISC stand for
Complex Instruction Set Computer
How does CISC work
Aims to complete the task in as few line of code as possible
How does CISC achieve completing code in as few lines as possible
Having higher quality hardware and circuity as it needs to be able to understand and execute a series of operations
How would a CISC processor execute a MULL (multiplication) instruction
It would load all the values into registers then multiply them together store the result and then output it
How much work does the complier have to do in a CISC processor? And what does it do?
Very little
Translate the high level language into assembly code
How many clock cycles does a CISC processor take to execute a line of code
As many as it needs but the lowest being 1
Where are CISC processors found today
In desktop Computers and Laptops but still very uncommon
What are the 2 disadvantages of CISC processors
- CISC processors are physically larger than RISC
- CISC can’t make use of pipelining
What does RISC stand for
Reduced Instruction Set Computer
What is the aim of a RISC processor
To use simple instructions that can be executed within one clock cycle
What doesn’t exist within RISC processors
Complex commands
E.g. MULL
How are bigger commands executed in a RISC processor? E.g. MULL
They are separated into smaller simpler commands
In a RISC processor how much work does the compiler have to do
A lot more than in a CISC processor
In a RISC processor why is more RAM needed
To store assembly instructions
What is a major benefit of RISC processors
Each instruction can be completed in a single clock cycle
Why do RISC processors have more space left for general purpose registers and cache
Less space is required for complex hardware
In a RISC processor. Why is pipelining possible?
All instructions are a uniform size
Do RISC processors have a lower energy requirement than CISC
Yes
What type of processors use RISC
ARM processors make up over 90% of all processors
What devices use RISC processing
Handheld devices such as phones and tablets
What does GPU stand for
Graphical Processing Unit
What do CPUs call the GPUs
A co-processor
What does a GPU do
Takes a load off of the CPU
Are GPUs still used for graphical processing
No
How does a GPU take load off of the CPU
Co-processors / GPUs are designed for specialised tasks that can be executed extremely fast
How many stream processors do GPUs have and how do they work compared to CPUs
Thousands and typically they run slower
What sort of operations are CPUs good at
Complex operations with small amounts of data
What sort of operations are GPUs good at
Simple operations on a large amount of data
What sort of processor are GPUs classed as
SIMD
What tasks are GPUs typically good at
- 3D arithmetic using XYZ calculations
- Storing XYZ positions
- RGB colour calculations
What is one benifit of doing calculations on a GPU
Can be done in parallel and doesn’t rely on other calculations
What are GPUs commonly used for
- Gaming
- Statistical analysis
- Oil explorations
- Stock predictions
- Weather modelling
- Machine learning
- Linear algebra
- Crypto mining
What is a multicore processor
A single chip containing 2 or more independent processing units
What can each core do
It’s own fetch decode and execute cycle
What is a CPU with multiple cores in it called
CMP
What does CMP stand for
Chip Multi Processor
What is the name of a processor with 2 cores
Dual-core
What is the name of a processor with 4 cores
Quad-core
How can a multicore processor be further enhanced
- Inter-core communication
- On-chip shared cache
Does a multicore system process multiple instructions faster than a single core system
Yes
How does parallel processing work
Processing program instructions by dividing them between multiple processors or processor cores
How do the two ways of parallel processing work
- One core fetches the instruction the next core decodes it and the third executes it
- One core that fetch’s and decodes all the instructions and then all other cores execute these instructions
How does the speed of parallel processing increase as you add more cores
It’s cumulative
