Choice, Use & Performance of Internal Components (2024)

1. CPU

As we learnt in our first lesson, the CPU is the brains of the computer. It’s job is to execute the instructions that make up the software programs running on our computer.

The performance of the CPU is affected by three main factors:

• Number of Cores – originally a CPU would have 1 core. Nowadays you can have 2, 4 or even more cores. A 1 core processor can only process 1 instruction at a time. If you have a 4 core processor you can process 4 instructions at a time. This obviously provides great performance boots. Technically this is made slightly more complicated by threads, which allow a single core to process 2 instruction at a time rather than 1. This gives even better performance.
• Clock Speed – this is how many cycles your CPU cores can perform per second. Each cycle the core can perform a single operation. So, the more cycles per seconds, the more operations per second, and therefore, the faster the CPU. We measure clock speed in hertz (Hz), 1Hz being 1 cycle per second. A 3GHz (Gigahertz) clock speed would mean 3 billion cycles per second.
• Cache Size – to perform an operation, the CPU needs to fetch an instruction from memory. If this comes from main memory (RAM) then there is a delay while the data is located & transferred to the CPU. This could take dozens of clock cycles. So CPUs will also have a small amount of very fast memory stored on the CPU itself. This is called Cache and an instruction can be passed from it to a CPU core in a single cycle usually. The more Cache, the more instructions that can be stored in it, and so the faster our CPU.

When choosing a CPU, we often mostly consider these above performance factors. At the very least we want a CPU that is powerful enough to run the software we require.

We also need to consider the processor socket your motherboard has, as not all CPU’s match all sockets. The 7th generation Intel CPUs require an LGA 2066 socket, whereas 6th generation Intel CPUs require a LGA 1151 socket. Choose the wrong CPU for your motherboard and it just won’t work.

2. RAM

The main memory of your computer is where data is stored before it is processed by the CPU. The main memory in your computer is almost certainly made up of RAM (Random Access Memory).

The main memory in your computer is volatile. This means that if your computer is turned off, the RAM will forget what it is storing. This differs to persistent storage, such as a hard disk drive, which will retain what it is storing even when the device is turned off.

The performance of the RAM is affected by two main factors:

• Memory Size – because all of our active software & files will need to be loaded into RAM, this can require a huge amount of memory. It is now common to have 8GB of RAM and you can have much more. If your RAM isn’t large enough to store all your active data, then your computer will fall back on Virtual Memory. This is an area of your storage device that acts as additional memory. This is much slower, so the more you end up using virtual memory, the slower your devices performance.
• Memory Speed – all RAM has a clock speed (just like a CPU). This represents how much data RAM can store & retrieve per second. Obviously the faster the better. This is measured in Hz, such as 3000Mhz DDR4 RAM. The clock speed isn’t the only measure of speed. There are also timings. Timings represent the number of cycles for the RAM to do something. So your RAM speed is really a combination of it’s clock speed (how many cycles per second) and it’s timings (how many cycles to do something).

When choosing RAM, the most important factor is almost always the memory size. This is certainly the biggest factor on performance. Memory speed doesn’t really have a massive noticeable effect on performance usually.

Another factor is the compatibility of the RAM with your motherboard. There are different version of DDR RAM, such as DDR3 & DDR4. DDR4 is a more recent version than DDR3 and provides, amongst other benefits, faster clock speeds & the ability for greater memory sizes. However, if your motherboard has DDR4 RAM slots, then you won’t be able to use DDR3 RAM with it, and vice versa.

3. Graphics Card

The most common type of expansion card used in a PC is a graphics card. This provides far greater graphics processing capabilities. A graphics card contains two major components to support this. The GPU (Graphics Processing Unit) & the VRAM (Video RAM).

The GPU & VRAM allows us to reduce the load on our CPU and RAM respectively and are also specialised for performing graphics processing much more efficiently.

The performance of the graphics card is affected by two main factors:

• GPU Cores/Clock Speed – a specialised processor designed to perform graphics processing, such as rendering 3D graphics on your screen. Unlike a CPU, GPUs can have thousands of processor cores. This is because graphics processing involves performing many similar operations in parallel (at the same time). The clock speed will actually be slower on the GPU than your CPU, though still, the clock speed still affects performance significantly.
• VRAM Size/Clock Speed – VRAM is used to store data the GPU will need to render images, such as textures & the frame buffer. VRAM will often come in similar sizes to RAM. A GeForce 1080 Ti will have around 11GB of RAM. However. VRAM is more optimised for graphics processing tasks and also tends to have a faster clock speed than RAM.

When choosing a graphics card, it is a pretty straightforward process. We obviously want a powerful GPU, and a large amount of VRAM.

Connecting the Graphics Card to your motherboard will be done using a PCI Express expansion slot, which your desktop motherboard will almost certainly have. There are different types of PCI Express slots, but they are backwards compatible, so you’ll still be able to connect your modern graphics card in an older slot (albeit with a hit on performance).