The workspace between storage and processor
RAM stands for random access memory. In a PC, it is the main working memory, also called system memory. It sits between the storage drive, where data lives permanently, and the processor, which does the calculating.
A useful comparison is a desk. The storage drive is a filing cabinet that holds everything you own. RAM is the desk where you spread out the documents you are working on right now. The processor works on what is on the desk, not on what is in the cabinet. A bigger desk lets you have more open at once, but it does not make you read faster.
RAM is much quicker than a drive to read from and write to, and it is volatile: it loses everything when the power goes off. That is why games must be loaded from storage each time you start them.
What a game keeps in RAM
When a game runs, a good deal of its working data sits in system memory, such as:
- The game’s program code that is currently in use.
- The state of the game world: positions of characters and objects, quest progress, inventory, and the details of the current level.
- Assets that the processor needs, such as animation data, audio, and collision shapes used for game physics.
- Copies of data on the way to the graphics card. Textures and models usually pass through system memory before being placed in the graphics card’s own memory, which is covered in the discussion of video memory.
- Data for the operating system and for any other programs running at the same time.
Notice that the game is not the only user. Web browsers, chat programs, launchers and recording software all take their share, and these can add up to a surprising amount.
Why loading depends on it
During a loading screen, the game reads data from storage into RAM and prepares it. If there is plenty of RAM, the game can keep more of its world ready at once, so it may need to go back to the drive less often. That can help with load times and with streaming in large worlds, although the drive’s own speed matters as well.
What happens when memory runs out
If programs ask for more memory than the computer has, the operating system has a fallback. It moves some less-used data out of RAM onto the storage drive, in a file often called a page file or swap space, to free up room. This is known as paging or swapping. When that data is needed again, it has to be read back in.
Because a drive is far slower than RAM, even an SSD, this swapping can cause problems you can feel:
- Stutters or freezes when the game needs data that is no longer in RAM.
- Long pauses when switching between programs.
- Slowdowns that get worse the longer the computer has been running with many programs open.
In extreme cases the computer may become unresponsive, or a program may close because there is no memory left. Stutter has many possible causes, though, so it should not be assumed to be a RAM shortage. A busy processor, a hot component or a full video memory pool can produce similar symptoms. Your operating system’s task monitor can show how much memory is being used, which helps you check.
How much RAM is enough
The needed amount depends on the games you play and what else you run. Many modern games publish minimum and recommended memory amounts in their requirements, and those are the best guide for a particular title. If you often keep a browser, chat and other programs open while playing, you may want more than the game alone suggests.
Extra memory beyond what you use gives no benefit in itself. A computer with far more RAM than it needs will not run a game faster. This is a common misunderstanding: RAM stops being a limit once there is enough, and adding more at that point does little.
Speed and configuration
Capacity is the first thing to look at, but memory also has speed, usually expressed as a transfer rate, and timings that describe delays. Faster memory can help some games, especially those that depend heavily on the processor, since the processor reads from memory constantly. The gain is often modest and varies by game and processor.
Another detail is that memory modules are typically installed in pairs, which lets the processor use two data channels at once for more bandwidth. A single stick on its own often leaves performance on the table. The motherboard manual normally shows which slots to use. Planning memory as part of any upgrade decision is sensible, because the motherboard limits which type and speed it supports.
RAM versus other memory
It is easy to mix up the different kinds of memory and storage in a computer:
- RAM (system memory) is the temporary workspace for the whole computer.
- Video memory belongs to the graphics card and holds data for drawing.
- Cache is a tiny, very fast memory inside the processor.
- Storage is the drive that keeps data permanently.
Buying more of one does not substitute for another. Adding RAM does not increase the graphics card’s own memory, and a faster drive does not replace RAM.
Consoles and shared memory
Game consoles are designed differently. Many use a single pool of memory shared between the processor and graphics, so there is no separate split between system and video memory. This is one reason console specifications do not map neatly onto PC ones.
Checking and managing memory use
- Look at your task manager or activity monitor while a game runs, to see how much memory is in use and by what.
- Close programs you do not need, especially browsers with many tabs.
- Check that your memory is running in the mode your motherboard supports; sometimes it is set lower than its rated speed by default.
- If a computer constantly runs near its limit, adding memory is a relatively simple and common fix, provided your motherboard supports it.
Summary
RAM is the short-term workspace that keeps a game’s data within the processor’s quick reach. Having enough lets the game run smoothly in the background of everything else. Running short forces the computer to use storage as an emergency overflow, and that is when stutter appears.