5.2.3 factors affecting processor performance
2 buses: 16 bit 32 bit size: 64bit
16bit 4 trips 32 2 trips 32 bits does it in 2 trips, quicker, increased performance
What is meant by 4GHz?
4 billion instructions are fetched decoded and executed per second
How does number of cores affect cpu performance?
Allows multiple iterations of the fetch-execute cycle to be performed simultaneously.
what is the advantage of a 4 core cpu to a single core?
If a CPU has multiple cores then a task can be divided between all of the cores or the cores can perform separate tasks/spread the workload individually overall leading to more fetch-execute cycles being iterated in a given time frame and therefore a better performance. ie 50 in 10 secs for single 900 in 10 secs for quad
What are the six factors that affect processor performance?
The number of cores The amount and type of cache memory (L1,L2) Clock speed word length address bus width data bus width
What is cache?
Very fast memory which can be quickly accessed by the CPU
What can an increase in cache cause to performance?
increasing the size of the cache means the quicker the CPU can fetch data meaning execution time is also decreased, increasing processor performance.
By increasing the width of the bus channels:
means more memory locations can be accessed and also means more bits can be transferred simultaneously and therefore increases performance
The greater the clock speed,
more fetch execute decode cycles happen within a given time frame
the higher the word length
the greater the amount of data that can be handled by one pulse of the system
What is meant by word size?
the number of bits the CPU can process simultaneously
What is clock speed?
the number of fetch-decode-executes that happens in a second (Hz)