CPU Performance | Computer for GCSE/IGCSE - Year 11 PDF Download

CPU Performance

• Central Processing Units (CPUs) can be equipped with multiple cores.
• A dual-core processor contains two cores, while a quad-core processor comprises four cores.
• Each core functions independently, executing fetch, decode, and execute cycles simultaneously.
• Parallel processing occurs when multiple cores execute tasks concurrently.
• Having multiple cores allows for multitasking, enabling the execution of multiple programs simultaneously.
• However, certain programs cannot be divided among cores effectively.
• The greater the number of cores in a computer, the higher the number of instructions executed per second, leading to improved performance.

Clock Speed and Performance

• Clock speed denotes the number of instructions a core can execute per second.
• It's measured in Hertz.
• Present-day cores have the capacity to execute billions of instructions per second.
• A gigahertz (GHz) represents a billion instructions per second.
• Conversely, a megahertz (MHz) signifies a million instructions per second.
• For instance, a CPU core operating at 3.4GHz can execute 3.4 billion instructions per second.

Cache Memory

Cache refers to a small memory located within or nearby the CPU, boasting rapid read/write speeds.

• It serves as storage for frequently accessed instructions/data, recently utilized instructions, and those slated for immediate fetching and execution in a process.
• Increasing the cache size enables storing more data, which can be accessed faster than if residing in RAM, thereby enhancing CPU performance.

Processor Cores

• Doubling the number of cores doesn't always equate to a doubling in the number of instructions executed per second. Variations in core clock speeds and cache sizes can influence this outcome.