Factors affecting performance Flashcards
How does clock speed affect performance?
The Fetch-Execute cycle is triggered by the clock pulses of the system clock
The faster the clock speed, the faster a computer can fetch, decode and execute instructions
what is a system clock?
A series of regular ON/OFF signals are used to synchronise the operations of the processor components
what is a quad core processor and how is it effected?
A quad-core computer has four linked processors
Each core is theoretically able to process a different instruction at the same time with its own fetch-execute cycle, making a quad-core computer two or even four times faster than a single-core computer
what is parallel processing?
Using several processor cores working at the same time is known as parallel or concurrent processing
In systems designed for parallel processing, each core can work concurrently on different parts of the same task
What is cache (level 1 and 2)?
Cache is a small amount of superfast (but expensive) memory that stores data and instructions that have recently been used by the processor
Level 2 cache is larger but not as fast as Level 1 cache
Level 1 cache memory is split into instruction cache and data cache, so that data and instructions can be fetched simultaneously
How does cache affect performance?
The more cache memory a computer has, the more likely it is that it will not have to fetch the next instruction or data from RAM, as it will already have been loaded into the superfast cache memory from which it can be retrieved much more quickly
what is pipe-lining?
This is a technique used to improve performance, for example by overlapping stages in the fetch-execute cycle, or by breaking down the stages in an arithmetic instruction
An instruction enters the pipeline, and as soon as one stage has been completed, another instruction enters the pipeline
A third instruction then enters before either of the others is completed
what does the size of the address bus determine?
The size of the address bus determines the maximum size of RAM
what does the size of the data bus determine?
The size of the data bus determines the maximum size of an operand in an instruction
