Random-access memory is where all the data necessary to start programs, run operations, and save the results is being stored. That's why it's also called a computer's "primary storage" - it sets the groundwork for all other operations we may want to run.
The "random-access" in RAM means that we can write data or delete it really quickly. And it's that speed that makes RAM so important to the computer as a whole. You can't replace it with even the fastest of SSDs. Unlike other types of memory, the data stored in RAM is volatile. It will be lost the moment we turn the computer off.
Types of RAM
We've got a lot of different types of RAM currently on the market - DDR2, DDR3, DDR4, or LPDDR3, and LPDDR4 (Low-Power DDR, like the ones we can find soldered onto an ultrabook's motherboard). The number at the end of the DDR acronym (Double Data Rate) - which should be accompanied by one more short, SDRAM (Synchronous Dynamic Random Access Memory) - tells us which generation of memory we're dealing with.
In notebooks we basically have no say in what type of memory will be used, as specific motherboards accept only specific types of memory. However, if we sort through the parameters, we can choose between computers with older and newer DDR technology, as well as faster and slower memory speed.
To put it simply, the more recent the generation of our memory is, the smaller the voltage, and, in turn, energy consumption we get. At the same time its clock speed goes up, making the whole thing more efficient. For example a DDR3 1600 MHz stick will be slower than a DDR3 2133 MHz, while a DDR4 2133 MHz can't hold a candle to a DDR4 2666 MHz.
It's worth remembering that if we want to buy more RAM on our own, we have to choose the type that is accepted by our laptop's motherboard.
It's a very important question, as the amount of RAM we have dictates how comfortable our work with a notebook will be. The higher the number, the more programs we'll be able to have opened without any slowdowns.
If our computer is running out of memory it will create a virtual RAM file, called a swap file that will be used to store all our necessary data. The only problem is that it's considerably slower than normal RAM, because it's using the HDD/SSD.
To avoid this bottleneck, our laptop needs a sufficient amount of RAM. Today, the minimal amount of RAM installed in computers is 4 GB. It's said that such a number should be enough for everyday or office use. What's interesting is that it's the amount you'll find in the cheapest of laptops, but also in the less expensive versions of high-priced computers like the Microsoft Surface Pro.
However, in practice, it may not be enough. Open up 10 tabs in your web browser, a text editor, and maybe one more thing, and suddenly your computer starts running at a snail's pace. Notebookrank.com recommends considering 8 GB of RAM as a safe minimum in 2021.
Gamers should aim for laptops with 16 GB of RAM, but if you're looking for a powerful notebook capable of handling 4K video editing, you should double that amount.
Upgrading or replacing RAM
How much RAM are we going to have depends on our computer's design. Compact notebooks, like ultrabooks for example, don't give their users the opportunity to upgrade, or replace RAM at a later time. That's why before we buy one, we should think long and hard whether our 4 GB of RAM will still be "the bare minimum" in 3-4 years, or should we go with something more powerful.
We shouldn't have to deal with such dilemmas if we own a bulkier, or gaming laptop. We can have 4 or 8 GB of RAM and upgrade or replace it ourselves any time we want. Careful: to do so it may be necessary to remove the whole bottom panel of our laptop, not just one cover. Therefore, the less manually proficient notebook users should leave that to professional service centers.