System Performance
Learn how we can improve the performance of a computer system
Introduction
System performance refers to the overall effectiveness and speed at which a computer system can execute tasks.
In this section we will look at how the following affect the performance of a computer:
- Number of processor cores
- Width of the data bus
- Cache memory
- Clock speed
Number of Processor Cores
A CPU can contain multiple cores. Each core contains a control unit, an ALU, and registers.
Many computers typically have two (dual-core) or four (quad-core) processors. However, modern processors can feature significantly more, with some having 20 or even 24 cores.
The more cores a processor has, the more instructions it can execute simultaneously, leading to improved system performance.
However, Simply doubling the number of cores won't necessarily result in doubling a computer's speed. The cores need to communicate with each other through specific channels, which can reduce some of the potential performance gains.
TODO: INSERT IMAGE OF CORES AND CHANNELS
Width of the Data Bus
The data bus is a series of wires that connect the processor and main memory, allowing for the transfer of data.
The width of the data bus is the number of wires that are used to transfer data.
An 8 bit data bus can transfer 8 bits of binary at once. A 16 bit data bus can transfer 16 bits of binary at once.
TODO: INSERT IMAGE OF DATA BUS WIDTHS
Therefore increasing the width of the data bus increases the amount of data that we can transfer at the one time. This will increase system performance
Cache Memory
Cache is a small, fast memory located within or very close to the CPU, making it more accessible than RAM. It temporarily stores instructions and data that the CPU is likely to reuse soon.
Before accessing RAM, the CPU's control unit first checks the cache for needed instructions or data. This reduces the need to repeatedly fetch information from RAM, which is a slower process that can cause delays.
Since transferring data between the CPU and cache is much faster than between the CPU and RAM, having more cache allows more data to be stored closer to the CPU, improving system performance.
TODO: INSERT IMAGE OF CACHE MEMORY CLOSER THAN MAIN MEMORY
Clock Speed
Clock speed refers to how fast a CPU can execute instructions, measured in hertz (Hz). It represents the number of cycles the CPU completes per second. A higher clock speed means the CPU can process more instructions in a given period of time, potentially leading to faster performance.
Each cycle allows the CPU to perform tasks like fetching, decoding, and executing instructions. 1 hertz represents one cycle per second.
CPUs are usually measured in GHz (gigahertz), which indicates how many billion cycles they can complete per second. For example, a CPU with a clock speed of 3 GHz completes 3 billion cycles per second.