CPU and System Performance

Central Processing Unit (CPU)

The CPU is often referred to as the ‘brain’ of the computer, and it carries out most of the processing inside a computer.
To a large extent, the speed of the CPU dictates the speed of the computer as a whole.
The performance of the CPU is affected by several factors: clock speed, the number of cores, and the amount of cache.

Clock Speed

The clock speed, measured in Hertz (Hz), determines the number of instructions a single core can carry out per second. For example, a 1 GHz processor can perform 1 billion instructions per second.
An increase in clock speed leads to an increase in performance, because more instructions can be executed each second. However, this also generates more heat, which can lead to overheating.

CPU Cores

A core is a part of the CPU which can process instructions. Modern CPUs may have two (dual-core), four (quad-core), or even more cores.
Each core can process an instruction separately from the others, meaning a multi-core CPU can perform several instructions at the same time - this is known as parallel processing.
Having more cores increases the performance of the computer, particularly for tasks which can be broken down into separate parts (e.g., video editing, playing video games).

CPU Cache

The cache is high-speed memory located on the CPU which stores frequently used data, allowing the processor to access it quickly.
A larger cache allows more data to be stored close to the CPU, which reduces the time the CPU has to wait for data to be retrieved from other parts of the computer.
Therefore, having more cache generally improves system performance.

Understanding Processor Performance

It is important to remember that different applications and tasks require different mixes of these factors to deliver optimal performance.
For example, an application designed to perform a single task might perform best on a CPU with a high clock speed, even if that CPU has fewer cores.
On the other hand, an application that can split its workload among multiple tasks might perform better on a CPU with more cores, even if each of those cores has a slower clock speed.

Improving System Performance

Besides CPU factors, there are other ways to improve the overall performance of a computer system. This includes adding more RAM, utilising high-speed storage drives, and using a more powerful graphics processing unit (GPU).
Similarly, keeping the computer’s operating system and applications up-to-date, as well as regularly performing system maintenance, can enhance system performance.