Factors Affecting CPU Performance
Computer Science: OCR A Level, topic 1.1.5
Factors Affecting CPU Performance
Not all Central Processing Units (CPUs) will execute code at the same speed. Some processors will be faster than others depending on the following factors:
Clock speed
- The CPU's clock sends a pulse at fixed intervals to trigger the next stage of the fetch, decode, execute (FDE) cycle.
- The higher the clock speed, the more pulses are sent per second, so more instructions can be executed in the same amount of time.
Cores
- Each core of a CPU is capable of processing instructions independently.
- Each core has its own Control Unit (CU), and Arithmetic and Logic Unit (ALU), but the cores share access to cache and main memory.
- Multiple cores allows a CPU to process multiple instructions at the same time.
Cache memory
- Cache memory is a small amount of very fast memory inside the CPU.
- In comparison to the cache, accessing the Random Access Memory (RAM) is a very slow operation.
- By storing frequently accessed data and instructions in cache memory we can avoid the process of accessing the RAM.
Test yourself on Factors Affecting CPU Performance
Which of the following will increase CPU performance?
Which of its three factors is most important for a high performance CPU?
Think of an answer, and then check the answer to compare it to your own.