Does more memory mean better performance? Yes, but not as much as you might think.

Most budget PCs come with at least 4GB of RAM. More powerful models will come with 8GB whilst modern gaming machines will go as high as 16GB RAM. When you consider that Windows 8 Pro can support up to 512GB it begs the question do you have enough RAM and how much do you need?

We all assume that adding memory makes a PC significantly faster, and in some cases it does. Sticking an extra pair of RAM chips into a motherboard won’t change the speed at which the processor works, but it can help, since adding RAM reduces the need for Windows to rely on “virtual memory”.

Virtual memory is a file on your hard disk that serves as temporary storage when your PC’s “real” memory is full. Virtual memory makes it possible to have several heavyweight applications running at once, even if they won’t fit simultaneously in RAM. When you switch from one to another, Windows quickly swaps the relevant data from the disk into real memory, which explains why the virtual memory file is sometimes called a “swap file”.

However, with modern machines coming with multiple GBs of RAM, the need for Windows to swap between real and virtual memory is reduced. In fact tests have shown that when a modern PC runs several major applications at once the total RAM usage never topped 4GB. This means Windows didn’t need to fall back on virtual memory at any point, and indicates that installing more RAM would give only a modest speed boost.

So should avoid paying for more than 4GB?  If you make heavier demands on your system, you may well benefit from more memory than this. For example if you edit video files, or work on large databases, or simply have 20 tabs open in your web browser you would benefit from having more RAM.

For current tasks, however, adding memory beyond 4GB yields diminishing returns. Outside of extremely specialist data-processing tasks, it is unlikely that you will need the benefits from 16GB. Therefore, before you spend your money consider that 4 or even 8GB of RAM will do everything you need with ease and save you money in the long term.