1.1.2 Flashcards
What factors affect the performance of a computer system ?
- Cache memory
- Clock speed
- Number of cores
How does cache memory improve performance ?
Cache memory is closer to the CPU than RAM. Therfore, it can provide data and instructions to the CPU at a faster rate
Does a computer with more cache memory have a higher performance, and why ?
A computer with more cache memory should have a higher performance because repeatedly used instruction can be stored and accessed faster
What is the limitation of cache memory ?
It’s costly, so most computers only have a small amount
What is clock speed ?
A measure of how quickly a CPU can process instructions
What is clock speed measured in ?
Give an example
It’s measured in Gigahertz (GHz). E.g. a computer night have a clock speed of 3.9GHz. This means it can perform 3.9 billion cycles a second.
How does clock speed improve performance ?
The faster the clock speed, the faster the computer can perform the FDE cycle. This means more instructions can be processed per second resulting in better performance.
What is overclocking ?
Overclocking is when the computer’s clock speed is increased higher than the recommended rate.
How does overclocking affect performance ?
Overclocking makes the computer perform faster but could cause damage to the machine and overheating.
What is underclocking ?
Underclocking is when the computer’s clock speed is decreased lower than the recommended rate.
How does underclocking affect performance ?
Underclocking makes the computer perform slower but will increase the lifespan of the machine.
What is a core, and its purpose ?
A complete set of CPU components - CU, ALU and registers. Each core can perform its own FDE cycle/
How does the number of cores improve performance, why ?
A computer with moire cores can process more instructions at once resulting in higher performance.
A quad-core can execute 4 instructions at the same time.
What are the limitations of having more cores ?
- If one core is waiting for another core to finish processing, performance may not increase.
- Some software may not be written to make use of multiple cores, so won’t run quicker on a multi-core computer.
