If you have a PC, or even a console that allows it, chances are it's not that easy to actually run out of memory.
Because, several decades ago, someone hit upon the idea of virtual memory.
Virtual memory is great. It allows you to pretend you have way more memory than you actually do, and the OS fills in the shortfall by figuring out what you actually are using at any one moment and taking the stuff you aren't using out of memory and putting it on the hard drive temporarily.
for most computer programs, this is fine, and really only a positive thing.
For games, however, it can cause serious problems.
If you have 3gb, and your game needs 3.1 almost all the time to run, the OS will go crazy swapping stuff into and out of memory constantly.
And since, as the article mentions, RAM is about a million times faster than a hard disk, guess what happens to your game if it starts to need virtual memory?
Though, lack of memory can hurt you more than you might think.
I had a laptop once with 1 gb of ram.
Loading times for some games would take many minutes.
Then, I switched it to 4 gb, and suddenly it took a matter of seconds instead.
So, that's another think with performance problems.
The source of the problem isn't always what you might expect.
(Would you expect loading times to improve from adding more RAM to a system?)
In general, you can see that computer hardware follows the 'weakest link' rule.
Whatever the weakest component in your computer is, that will usually be what limits how well a game runs on your computer.
Of course, in reality, games are very unpredictable in how much demand they put on different components.
If a game does a lot with the GPU but very little with the CPU, you might not notice that the CPU is weak, because almost nothing is being done with it.
And some components have more... Specific effects. A slow hard drive will slow down loading times, but probably won't have much effect on anything else. (unless you have another problem as well.)
Slow RAM might be a problem, but only if a lot of information is being read and modified repeatedly.
(Which GPU's do a lot of, which is why GPU manufacturers often boast about 'memory bandwidth' - Because creating an image that's the combined result of 20 different 4096x4096 textures requires A LOT of memory reads... XD)
Then of course, there's endless arguments to be had about performance.
Even if something runs, how slow is too slow?
Where do you draw the line between what's playable and what isn't?
And honestly? that line varies depending both on the person playing, and the nature of the game.
(A fast-paced action game needs a much higher framerate than something like virtual chess. VR needs 90+ FPS for entirely different reasons to the usual arguments made about framerates. And so on.)
I used to find it perfectly OK to play games that hovered in the 15-20 fps range...
Some people might find that completely intolerable...
Clearly, what qualifies as 'obsolete' in that sense depends on what your expectations are.