Random access memory (RAM) is a computer's short-term memory. None of your programs, files, or any online streams would work without RAM, which is your computer’s working space.
What does RAM stand for?
RAM is short for “random access memory” and while it might sound mysterious, RAM is one of the most fundamental elements of computing. RAM is the super-fast and temporary data storage space that a computer needs to access right now or in the next few moments.
Computers are always loading things in to work on — such as applications and data — and then setting them aside for later. RAM is your computer’s short-term memory. In contrast, a computer’s hard disk or SDD is its long-term memory, where things are stored more or less permanently.
Every computing device has RAM, whether it’s a desktop computer (running Windows, MacOS, or Linux), a tablet or smartphone, or even a special-purpose computing device (such as a smart TV). Nearly all computers also have some way to store information for longer-term access, too. But the working processes are done in RAM.
What does RAM do, exactly?
RAM is temporary storage that goes away when the power turns off. So what is RAM used for, then? It’s very fast, which makes it ideal for things the computer is actively working on, such as applications that are currently running (for example, the web browser in which you’re reading this article) and the data those applications work on or with (such as this article).
It can help to think about RAM with the analogy of a physical desktop. Your working space — where you scribble on something immediately — is the top of the desk, where you want everything within arm’s reach and you want no delay in finding anything. That’s RAM. In contrast, if you want to keep anything to work on later, you put it into a desk drawer — or store it on a hard disk, either locally or in the cloud.
Ultimately, RAM allows you to access multiple programs at once with speed and efficiency.
RAM is significantly faster than a hard disk — twenty to a hundred times faster, depending on the specific hardware type and task. Because of its speed, RAM is used to process information immediately. When you want to accomplish a specific task, computer operating systems load data from the hard disk into RAM to process it, such as to sort a spreadsheet or to display it on screen. When it’s done actively “doing something,” the computer (sometimes at your instruction) saves it into long term storage.
So, for example, let’s say you want to work with a spreadsheet. When you start Excel, your computer loads the application into RAM. If you load an existing spreadsheet (which is stored on your hard disk), the operating system copies that information into RAM, too. Then you can work with Excel, crunching numbers in your usual fashion. In most circumstances, the computer responds super-fast, because RAM is fast. When you’re done with the spreadsheet, you tell Excel to save it — which means that the data gets copied to the hard disk or other long-term storage. (If you forget to save and the power fails, all that work is gone, because RAM is temporary storage.) And when you close the application, the computer operating system takes it out of RAM and clears the deck so that the space is free for you to work on the next thing.
One extended use of RAM is to help previously-accessed information be available much more quickly. When you first turn on your computer and launch any application, such as PowerPoint or Spotify, it takes a while to load. However, if you close a program and then relaunch it, the software opens almost instantly (unless your PC isn’t optimized for performance). That’s because the app is loaded out of the significantly faster RAM, rather than the hard disk.
One notable example is the operating system’s own process. For example, if you use Windows, its key functions — such as the ability to display images on your screen — are copied into RAM, because the OS needs super-fast access to the devices you use all the time. Not every device driver is loaded into RAM immediately, but many of them are.
Another example is a Windows feature called SuperFetch, which records your usage patterns. Based on your existing behavior, it automatically pre-loads applications and files into RAM when you turn on your PC. This makes working with your computer significantly faster.
When an application needs a lot of RAM, it often gives you a progress bar or other status report. That’s common when you load a game or powerful application. When you launch a game, you may see a “loading” screen while the computer copies information into RAM, such as maps, character models, and objects. That “loading” message is displayed to ensure you know something is happening, when the developers cannot make the process instantaneous!
How much memory do we need?
The more RAM a computing device has, the faster it runs. If your device is old, you might need toupgrade the hardware. Every open application (including tabs in a web browser) consumes RAM. You can run out — and when that happens, the computer has to move things around on the hard disk, which slows down the computer.
Note that RAM is different from storage: if you turn off your PC, the information is gone whereas on storage (SSDs, HDDs…) that data will be saved.
How much RAM do we need?
It depends on the kind of work you do, how many things you do at once, and how impatient you are. As with so many other parts of computing, we always want our devices to respond instantly!
In most circumstances, however, you need far less RAM than you do hard disk space. Again, think of that physical office desk. The more space you have on the desktop, the more pieces of paper you can spread around. But that doesn’t keep you from wanting a very big file cabinet for long-term storage of all the files you’ve collected over time.
Once upon a time — say, 25 years ago — when common hardware was based on Pentium CPUs, you rarely needed more than 8MB of RAM — perhaps 32 MB if you were a serious tech geek. That was plenty to run Windows 95, the first Windows versions of Word, and Doom.
Today, a web browser with 10-20 open tabs can easily consume over 2200 MB — or 2.2 GB — of RAM.
When you buy a computer, generally you have several options: 2GB, 4GB, 16GB or even more memory.
Most lower-end devices come with 4GB memory today, while higher-end (and thus more expensive) machines have 8GB or 16GB of RAM standard. (You can usually add more at an increased price.)
But how much do you really need and for what? Here are our recommendations, which apply to any operating system or personal computer hardware:
4 GB of RAM:If you’re only browsing the web, working with basic Office applications and maybe dabbling a bit in personal photo editing, you’ll be fine with 4 GB of memory.
8 GB of RAM:Heavy multitaskers or light gamers should choose a computer with 8 GB of RAM.
16+ GB of RAM:Some tasks are inherently computing intensive, such as serious gaming, video editing, and programming. “Enthusiast” users who never want to experience slowdowns will need 16+ GB of RAM to be happy.
When the computing tasks exceed the current amount of memory on the computer, the operating system moves a less-actively-used application onto the hard disk temporarily. When you switch back to that application, it needs to retrieve that information before you can work with it. This is calledpagingorswapping, and it’s time-consuming. The process causes delays and losses in performance.
You can make your computer run faster and better by regularly clearing wasteful clutter out of your RAM.
Are there different types of RAM?
Yes, there are multiple types of RAM! As with other forms of computer hardware, scientists are always trying to decrease energy consumption while they increase speed and capacity. RAM has been around since the first days of computing, and in early microcomputing eras it required enthusiasts to plug in chips one at a time.
By the late 1990s and early 2000s, users had their choice of static RAM (SRAM), Dynamic RAM (DRAM), or Synchronous Dynamic RAM (SDRAM).
Nowadays, the most common type is DDR-RAM, and there are various iterations, including DDR2, DDR3, DDR4, and DDR5. DDR stands for double-data rate and allows multiple file transfers at the same time. Current speeds are about 25 gigabytes per second for the latest DDR4-RAM.
There are also multiple types of speeds of DDR4 memory. By default, these memory sticks run at around 2500 MHz. If you want to squeeze the absolute maximum performance out of your memory, you can get higher clocked RAM. Nowadays you’ll find memory ranging from 2333 MHz up to 5000 MHz (which is interesting for gamers andGPU overclockers). The more MHz your RAM has, the faster it is!
Eventually, DDR5 will replace DDR4, as it has even further increased performance — about 50 GB/s.
There’s also VRAM (Video Random Access Memory) which sits on your graphics card and is used for loading graphical data (such as games). Video RAM is even faster than normal memory and comes in the form of GDDR5X or HBM memory with higher bandwidths.