CPU Performance (OCR GCSE Computer Science): Revision Notes
📚 Revision Notes
CPU Performance
CPU Characteristics & Performance
Clock Speed
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Clock Speed is the number of fetch-decode-execute cycles a CPU can complete in one second. It is measured in hertz (Hz), typically in gigahertz (GHz), where 1 GHz equals one billion cycles per second.
- A 3.6 GHz processor carries out 3.6 billion calculations a second.
Cache Size
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Cache Size is the amount of high-speed memory available to the CPU for storing frequently used data. Larger cache sizes allow the CPU to access data more quickly, improving performance.
- Cache memory is a buffer that sits between the CPU and main memory.
- The CPU will check here first for instructions that have been fetched before.
- The larger the cache, the more space there is for instructions the CPU needs
- The cache has similar access speeds to the CPU and is therefore quicker to fetch instructions from.
Number of Cores
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Number of Cores refers to the number of independent processors within a CPU that can work simultaneously. More cores allow the CPU to handle multiple tasks simultaneously, increasing overall performance.
- A dual-core has 2, quad-core 4, hex core 6 processors working simultaneously.
- The higher the number of cores, the better the performance of the computer as it can multitask.
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Key Points to Remember
- Clock speed measures how many cycles a CPU can perform per second, with higher speeds leading to faster processing.
- Cache size refers to high-speed memory in the CPU that stores frequently accessed data, improving performance with larger sizes.
- Number of cores indicates the number of processors within the CPU, with more cores allowing better multitasking and overall performance.