What is RAM and how does it work?
Whether it’s a laptop, desktop, phone, or game console, you’re basically looking at a computer, and there’s a lot of overlap in technologies at the interior. RAM, or Random Access Memory, is one of those technological elements that you will find inside each of them. Since it’s so universal, it’s worth knowing exactly what it is and how it works.
We’ll go into more detail shortly, but the TL; DR is that RAM is generally referred to as dynamic RAM. Active memory is filled with data that your computer is actively working with, which usually comes from running applications or files that you are currently viewing. The more data your computer uses at a time, the more RAM it will use.
If you run multiple programs at once or very demanding applications, you may use more memory than your computer has available, which can cause slowdowns and other problems. For most devices you’ll use, RAM is measured in gigabytes (GB), often between 2GB and 64GB (or even 128GB on high-end systems).
RAM can come in the form of memory modules soldered onto your system’s motherboard or removable modules called DIMMs that fit into a motherboard. Most compact devices, like laptops and mini PCs, opt for the soldered route for the space savings it offers, but larger systems like larger laptops and desktops opt for Modular DIMMs, which allow system RAM to be swapped and upgraded.
How does RAM work?
You need to be familiar with a few pieces of the puzzle to understand how RAM fits into a system: the processor, cache, RAM, and storage.
Ultimately, the data needs to access your CPU, or processor, to be processed. The system manages this data at different levels. Storage is where everything resides at all times, backed up for the long term and staying there even when your device is turned off. It would be your HDDs (hard disk) and solid state hard drives (SSD). Files, programs, apps, and games are all saved in storage. Confusingly, storage is sometimes referred to as memory, so be aware of that. If you see an affordable device listing more than 32GB of “memory”, it’s probably storage – 128GB of storage is an insignificant amount, but 128GB of RAM is more than excessive.
When you go to use an app, game or anything else, your system pulls data from storage and loads it into RAM. Memory is much faster than storage, so having data accessible here keeps the system running fast.
If you launch several different programs at once, they will all try to load into RAM. However, not all of them might be suitable. Your system will occasionally need to pull items out of RAM. If you’re switching between a lot of programs and you notice that one is taking a bit longer to reload, it may be because it’s been drained of RAM and needs to be removed from storage or swap memory (an area reserved on storage to hold memory that overflows RAM).
Now RAM is not actually where the data is processed. Ultimately, data is moved into cache, which is a small pool (often a few megabytes) of very fast memory actually built into the processor itself.
Understanding RAM in Simpler Terms
To put it in more relevant terms, think of this all as a math homework. Storage is your manual. It contains all the math problems, formulas and information you might need.
When you have a homework assignment, you write down all the questions and maybe jot down some of the relevant formulas you’ll use on a blank sheet of paper. This sheet of paper is your RAM. At any time, you don’t think of all the problems you’ve written on this paper, but you have access to them almost immediately if needed – no need to leaf through your manual to find what you need. When you work on solving any of the problems, you now think about this data right in your brain, i.e. your processor and your cache at work.
Types of RAM you’ll find
You will find RAM in almost every device you use that has an operating system, be it iOS, Android, Windows, or even a smart TV platform. Although it can come in many different forms, you’ll often get a clue that you’re looking at some sort of RAM if you see “DDR” listed followed by a number that indicates the generation. You can find many computers using DDR3, DDR4 and now even DDR5 memory. Some thin and light laptops and smartphones use low-power memory or LPDDR#. Graphics cards also have their own memory, with GDDR#.
For more information on selecting RAM for your system, check out our guide to the best RAM.
Mark Knapp is a regular contributor to IGN and an irregular tweeter on Twitter @Techn0Mark.