Random Access Memory (RAM) is used by the installed OS on a PC to store data from running programs for fast access.
Updated April 26, 2017: We've beefed up the guide with more information on speeds, latency, and how to decipher classification of RAM modules.
These components are installed directly onto the motherboard and are usually situated near the central processing unit (CPU). Here's why you need RAM, what is it good for, and how you go about upgrading it.
A RAM primer
The RAM inside your PC is incredibly important. It allows the motherboard (and installed OS) to quickly store and access data without going through slow (but spacious) hard drives. Even though we're rocking Solid State Drives (SSD) these days, RAM modules remain the best option when it comes to accessing data at speed.
But RAM is only meant to store data when it is needed — the process of opening a program is essentially that of copying the files from the storage to available memory. You can think of it like a desk: you store papers and tools in the drawers, but when you're going to need something like a stapler and a folder of bank statements, you take them out of the drawer and put them on the desktop until you are done and put them away. It's faster and easier to just keep the stapler out for as long as you need it than to put it back in the drawer after each time you use it.
Your PC will use the RAM to run Windows and the programs that you're using, so the amount you'll need will vary at any given time. You can quickly check how much RAM is being used by opening Windows' Task Manager, which can also show you how much RAM is free and how much is being used by each individual program. Don't feel like you have to immediately purchase more RAM if your system is using a fair amount (say 75 percent). Unless you're frequently maxing out the available RAM, it'd just be a waste.
But should your system be using all available RAM, the hard drive will be used as a backup to store and read data and emulate RAM — a "page file" or "virtual memory." While this enables you to do more even with limited RAM, even a speedy SSD is significantly slower than your RAM, and your computer's overall speed will suffer when it has to use your storage drive as an overflow for your RAM. In the desk metaphor, you've got too much on your desktop at once and you're having to constantly swap positions of stuff between the desktop and the drawer to keep going — you can have more going on, but it's slow, cumbersome, and wears on your drawers. If this is happening frequently, more RAM may be in order.
When to upgrade
If having close to all your RAM being used by the system is OK why and when should you upgrade and install more? The recommended amount of RAM for Windows 10 is 8GB, which allows for some degree of multitasking and light gaming. You shouldn't really encounter an issue with that amount of RAM unless you're hammering heavy programs like Photoshop and others on a frequent and simultaneous basis.
But if you hit the ceiling when the performance takes a fall, and you simply cannot push the system further than it's capable of going, you more than likely need to add some more RAM. First, we need to figure out just how much RAM you have, what configuration the modules are in, as well as other details like RAM type and clock speed.
The easiest way to check is to download a free tool like Speccy that will be able to tell you all of this. The components themselves usually come in sizes of 1GB, 2GB, 4GB, 8GB, and 16GB. These can be DDR, DDR2, DDR3 or even DDR4, depending on what your motherboard and CPU supports. DDR4 is the latest and greatest, but if your system happens to be DDR3 you'll be fine too. And even if you're running old DDR2 RAM, upgrading your RAM will provide a performance boost that still significantly costs less than buying a new PC.
Another way to check what RAM your PC supports is to check the manual for the motherboard, or even look up the model of the board on the manufacturer's website.
Crucial RAM Tool
Crucial has a handy tool that can check what RAM a specific laptop or desktop PC model supports and recommend upgrades. This is handy if you're not familiar with PC building, don't understand what RAM you need, or just want to have an automated system do all the leg work. The only issue with the Crucial tool is you're locked into the company's offerings. You'll want to go elsewhere to take advantage of other deals.
Speed and latency
Breaking down RAM classification is rather straightforward. DDR4 is simply a type of synchronous dynamic random-access memory (SDRAM) and is the latest standard available, succeeding DDR3. This allows for improvements like increased bandwidth, speeds, lower latency and voltage requirements. 2,133MHz is the clock speed of the RAM module, and the CAS 15 figure is the latency score.
All together you'll see the following in RAM listings: DDR4 2,133MHz CAS 15.
Using our walkthrough above, we can determine that this module is compatible with latest motherboards and processors (that support DDR4), is rated at a speed of 2,133MHz and has a latency score of 15. One more thing to watch out for when looking at RAM is the clock speed and latency. With RAM, speed is everything. The latency is essentially the delay between your computer asking the RAM to load a file, while the clock speed is how fast that action will happen.
The lower the latency and the higher the clock speed, the better. As with most things, the better versions are the more expensive ones. Don't feel that you must go for the best RAM if you're not doing a lot of heavy work with your PC.
More information on RAM speed and latency
Installing RAM
RAM can be installed in various configurations, depending on the motherboard. Modules can be installed in single, dual channels or even more. You can find some instances where motherboards can take anywhere up to eight sticks of RAM, making for quite the powerful rig. Depending on the RAM you purchased, you'll need to install the modules in corresponding slots.
For example, if you purchased two 4GB modules, these will need to be installed in the color-coded and labeled slots, while a single 8GB module can be thrown into a single slot and you're good to go. Before you do absolutely anything when it comes to installing RAM, you need to ensure the system is powered off and take appropriate anti-static measures. In general, though, you'll want all of your RAM to match in size and speed for optimal performance.
Once you've installed the new RAM, you need to hop into your motherboard Basic Input Output System (BIOS) – basically an admin panel of sorts – to ensure it's reading the modules correctly. Cross-reference frequency, capacity and other values between what you see on the screen and what's on the RAM packaging. You can figure out how to access the BIOS at boot by checking your motherboard manual.
The same goes for laptops and prebuilt PC systems, though limitations may be in place. With new RAM installed, you should be able to enjoy smoother gameplay, increased productivity and multitasking.
Reader comments
Ultimate RAM buyer's guide for Windows PC users
I upgraded mine when newegg had a sale. 32GBs that I'll probably never use, but I got a great deal!!!!!
I have 32GB too, bit of overkill but it's there if I need it. It also means I can run a Virtual machine with 8GB of RAM and not have any resource issues
Better purchase same RAM sticks. If the voltage and latency don't match, you may be in deep trouble.
It is always wise to purchase identical sticks of RAM, however, most motherboards now allow you to modify/adjust the voltage, latency and frequency of your RAM. So if you are piiecing a PC together of spare parts and the motherboard isn't something that belongs in a museum you should be fine. Older motherboards may not allow you to adjust the latency and frequency manually, most of them will default to the slower stick anyways. Otherwise if you are building new its always best practice to purchase identical RAM, as Pallav pretty much said, stability. You will save yourself from possible headaches and frustration.
The desk metaphor is a good example to explain RAM to non techies. 👍🏻
And he should have added that Amount of RAM is like desk space. The more the better.
Actually the hard drive will always be used by default even if the RAM usage is not maxed out. After I had my first 8GB of RAM I disabled the page file without noticing any side effects. This freed more space on my hard drive and helped boosting the speed of my computer.
Good idea if you have enough RAM. But nowadays with SSDs, removing page file doesn't make much difference, unless you are running a regular HDD.
Actually with SSDs I'm more inclined to disable the page file as I try to minimize disk writes and prolong the life of the drive. This reminds me, I need to recreate my RAM drive and use it for my browser cache and other temp folders. Maybe Windows Central can write about RAM drives next, which is a cool and useful feature. At least you can make use of all the RAM you are adding.
Ssd will last 10 years at 10gb write usage a day, your point is not as valid as it is used to be!
You must be doing quite less on your pc. 8 gb is kind of not enough for disabling Paging file. Nit even 16. Maybe a good 32 gb. Will hold the pc in good shape and out of the most of the problems that can occur with paging disabled. As about the ssd. I don't know why are people so scared of loosing this drive. I had an old rig with an old 128 gb ssd on board. The ssd has now about 4 years. It works like new and show no signs of wear. Actually, i bought a new pc and that ssd still functions. This hysteria of loosing an ssd so quickly is actually unfounded. The only thing i do is to keep my files on a good old mechanical drive, or yeah, on two.
Maybe you are right about SSDs, but for the page file I have been living without it for 4 years now and doing perfectly fine with 8 GB of RAM, even playing big games like Skyrim. Now I am still on Windows 7 which probably uses less memory resources than later systems.
32GB of RAM and no page file here either
Why purchase more ram when you can just download more ram. xD
PS: Up to Skylake/Kaby Lake, RAM speeds did not matter THAT much for gaming. But Sky/Kaby profit dramatically for high speed DDR4 ram, that means 3200+.
I am adding either 16 or 32 gb of ram to my new dell inspiron 13. Should be a great upgrade...and also the 1 tb SSD.
You seem like you're aiming this article at people who know very little about PCs and would never have upgraded or touched the inside of a PC. Yet with that in mind you didn't mention the notches on the RAM, something very simple which I've seen people completely miss to the extent that they actually damaged their RAM trying to fit it the wrong way. Also you have no pictures of you actually installing the RAM, something that might be of use to people who have never done this before.
Finally, you forgot about height. for example those lovely RipJaws you have won't fit under my CPU cooler, however the set of Corsair RAM I have does fit.
Because writing an article based on everyones PC configuration, CPU cooler, case size, type of PSU and GPU installed would be about a million pages long. If you are unable to look at an object and see a pattern to properly fit it you must have been that kid that kept trying to force the square peg in the triangular hole. Yes I do realize people are that stupid, and I don't understand how, but they are. However, I do agree on the lack of content/images on actually installing RAM for first timers.
That's the problem though isn't it? People who are first time RAM users might not notice the notch in the slot itself. Slot on the stick itself, maybe. As I stated, I've seen it happen and that's with people who aren't stupid. At no point did I ever say write an article covering everyone's PC, mentioning that you need to check if the RAM will physically fit with your cooler, the notch, and a couple of photos do not suddenly make the article explode in length.
The article on the whole is good, but to me it lacks some of the basics.
In no way did I mean my post as an attack on you, re-reading my post I see how my wording caused that, it actually makes me look like a d***.
"The article on the whole is good, but to me it lacks some of the basics."
I agree 100%
But in a world of instant online knowledge videos are abundant, and accessible from multiple devices. Perhaps they just wanted to reduce redundancy? I don't know.
Doubled my RAM on my all-in-one the other day to 8GB, I'm no expert with computers but it was the only thing I could see that might help my PC with some of it's struggles. It's made a good difference, nothing wow but worth the small cost for an extra 4GB.
That little modification may not be like the work of other guys who build their own super powerful rigs, but for a little moment I felt pretty damn clever.
**** RAM and have SSD .
And see your computer high
Crucial RAM is all I will ever buy
I see nothing noteworthy in here. No talk about the actually new instance where RAM has shown to be a big deal--overclocking and peak speed on Ryzen. Literally the biggest thing to consider when buying RAM right now, and nothing about it. How is this guide "ultimate?"
Note that with the Creators Update the Edge browser has improved security by running more of a web page's code in the tab instead of in the general Edge environment. My experience is that by opening multiple tabs with 4 GB your device bogs down, while 8 GB will do fine. So, using a less secure browser will do if you cannot afford the RAM upgrade.