System Architecture - The performance of the CPU Flashcards
What is the function of the CPU?
- To fetch, decode and execute instructions
- To process data
What affects the performance of a computer?
- Cache Size
- Number of Cores
- Clock Speed
- RAM
What is the part of a processor in which instructions are executed is known as?
The core
How many cores does a dual-core processor contain?
2
How many cores does a quad-core processor contain?
4
Do cores execute instructions together or separately?
separately
What are the benefits of a dual-core processor over a single core processor?
- Tasks can split between the processors…
- which leads to more processes being completed per second…
- this speeds up the computer
If the number of cores goes up from 2 to 4 – what is the exact effect on performance?
The maximum number of instructions executed per second doubles
What are the effects of using a processor with more cores?
- More instructions carried out simultaneously
- The processor can process more instructions at the same time, which allows batches of instructions to be executed more quickly, which allows for more programs to be run at the same time.
What acts as an intermediary between the processor and the Main Memory
Cache
What is cache?
Very fast, and usually a very small amount of memory on the processor chip
What is held in cache?
Commonly used instructions and data
How does the cache size affect the performance of the CPU?
- data is transferred faster (1)…
- …which makes a CPU more efficient (1)
- It is faster to transfer to and from cache (1)…
- …than transferring to and from RAM (1).
What is the purpose of cache memory?
- To store instructions / data that is frequently used
- Stores previously used / next to be used instructions and data
- Provides faster access to data and instructions than the RAM
- Speeds up access because instructions & data can be loaded to the CPU more quickly
What are the effects of using a processor with a bigger cache?
- More space available for frequently used instructions / data…
- this will reduce the number of disk transfers (fetching data from RAM)…
- which leads to faster fetching of data and instructions…
- which leads to faster processing
What is a processors clock speed?
The number of instructions a processor can carry out in a second
Hertz
What is a processors’ clock speed measured in?
A 1GHz processor can execute how many instructions?
1 Billion Instructions per second
A 2GHz processor can execute how many instructions?
2 Billion Instructions Per Second
If the processing speed goes up from 2GHZ to 4GHZ – what is the exact effect on the performance of the computer?
The maximum number of instructions executed per second doubles
If the processing speed goes up from 1GHZ to 4GHZ – what is the exact effect on the performance of the computer?
The maximum number of instructions executed per second quadruples
What does RAM stand for?
Random Access Memory
What is RAMs function?
- The computer’s main memory
- Stores data, applications and the operating system while in use
Is RAM Volatile or Non-volatile
Volatile - all the data is lost when the power is switched off
How would increasing the amount of RAM improve a computer’s performance?
- More instructions / programs / applications can run at the same time / be held in RAM
- Open software faster / respond faster
- More memory space for current programs
- Run more memory intensive programs / relevant example e.g. computer games / graphic rendering
- reduces use of Virtual Memory
- …..less use of hard drive which is slower to access
How could a installing a graphics card improve the performance of a computer
- It could carry out processes for the CPU
- It can improve the speed and quality of graphics
How could changing a computer’s hard disk drive (HDD) for a Solid State Drive (SSD)?
Faster read / write speed
If the processing speed goes up from 2GHZ to 4GHZ and the number of cores goes from 2 to 4 – what is the exact effect on the performance of the computer?
The maximum number of instructions executed per second quadruples
