Random-access memory or RAM is a special kind of memory, different from other common storage memory types – SSDs, HDDs, eMMC etc.
RAM allows for extremely fast access to data. It’s RANDOM ACCESS, meaning stored data can be accessed instantaneously regardless of its location on the data (storage) tree.
Think of an urban neighborhood. To get to house G by car in a street with houses labelled A – Z, you must navigate through and pass houses A – F. That’s traditional storage architecture.
With RAM, Navigation is by air, using a resident drone. To get to house G, the drone simply drops down to G. No need for twisty navigation but more importantly, the distance is shorter, the method of access is faster and overall, navigation (data retrieval) is swift.
Your PC leverages this super-fast data access and retrieval system to get all the data it needs to complete computing tasks. But like drones, RAM modules differ significantly. Some are faster than others, and some use smarter technology. Let’s get down to the basics, so you have all the information you need to pick the best RAM module for your needs and budget.
How much RAM do you need?
The more data a RAM stick is able to retrieve and store in a ‘hot’ state for speedy use by your CPU, the better. So obviously, with RAM, the general rule is more is better. But let’s get granular:
How much RAM is good enough in a laptop?
Today’s PCs ship with up to 64GB of RAM, and if you dive into the world of workstations, it won’t be odd to see a 128GB RAM setup.
For everyday PCs, 8GB of RAM is good enough. That’s enough to handle all forms of web surfing, programming, writing, document editing, graphic design work, casaul video editing, and mid-tier gaming.
If you’re doing mostly writing, video watching or Youtubing, you can get away with 6GB or even 4GB of RAM but expect the occasional lag and freeze.
For anyone who plans to do some performance heavy-lifting on their PC, I’m talking serious video editing work or gaming, the ideal setup is a 16GB RAM stick. You can go up to 32GB of RAM, and it’s fair to note that there’s a growing line of high-end consumer laptops shipping with 32GB RAM modules as standard. But, I won’t recommend shelling extra cash for a 32GB setup if you’re not doing extremely performance-intensive stuff. 16GB is fine!
What happens when you run out of RAM?
As I already noted, a larger RAM module allows your computer to store more of the info it needs to run smoothly at any one instance. When RAM space is small, your computer cannot store all of that data. Instead, it needs to pull data from your primary storage device manually.
This will result in longer processing times since SSD/HDD devices are not optimized for the insanely fast data retrieval you get with the RAM module. Ultimately this translates to annoying lags or freezes. Sometimes the RAM module might get completely overwhelmed, forcing all apps to close or, worse still, a PC crash.
Remember that the difference between small and large RAM space depends entirely on your needs and PC usage habits. If you’re the type to run fifteen apps on your PC in one go, then a laptop with a 4GB RAM setup might be less than ideal. But for the average writer or student who usually has, say, four-five low performance apps opened at once, a 4GB RAM setup can suffice.
Like basically any other PC/Laptop component, RAM technology has evolved through the years. You’re going to find that different PCs come with RAM modules spotting slightly (or grossly) different RAM specs despite having the same memory capacity. Let’s address some of those spec differences.
DDR3 vs DDR4
DDR stands for Double Data Rate, and it’s basically a description of the data transfer technology employed by the RAM stick. DDR4 or Double Data Rate version four is the current in-vogue protocol, and it’s the successor to DDR3 or Double Data Rate version three.
All things equal, DDR4 is faster and more energy-efficient than DDR3. It also has support for larger RAM space, with the cap for DDR3 modules being 32GB and DDR4 being unlimited. Most PCs on the market will spot a DDR4 RAM module, and I’ll generally advise against going for the few PCs that ship with a DDR3 RAM stick. There’s no backward compatibility between DDR4 and DDR3, so if you bought a PC with a DDR3 RAM stick, you can’t upgrade it to a DDR4 setup later in the future.
Released in 2020, DDR5 is the latest transfer tech for RAM modules. It is faster and provides better energy savings than DDR4. DDR5 is, however, yet to go mainstream. As I said, most of the RAM modules you’ll find on the market today will be DDR4-type. When you do find a DDR5 RAM stick, expect it to be significantly costlier than a DDR4 stick with the same capacity.
Because of this tendency to be costlier and because the performance upgrade from fitting your PC with a DDR5 module compared to a DDR4 alternative is not that great, sticking with DDR4, for now, is fine. The decision to stick with DDR4 is even easier to make when you understand that most consumer-grade PC/laptop components (CPUs and all the accessory bits) lack the technology to take advantage of DDR5 fully. This will change in the nearest future.
MTps and MHz – frequency
Most RAM modules will come with a naming scheme that looks something like manufacturer/RAM name/DDR4/3200. For example, the Corsair Vengeance RGB Pro DDR4-3200. The last bloc of numbers, in this example, ‘3200,’ is the frequency measured in either MTps or MHz.
MTps is a more objective unit than MHz, since MHz simply measures the number of electrical cycles completed by the module per second – MTps measures the actual memory-related tasks completed. That might sound confusing, but I go into details about frequency and how it relates to actual computing as it concerns computer chips in my guide to buying a CPU.
MTps stands for Mega Transfers per second, and from the name, you can see that it’s a measure of how much data a RAM module can transfer in one second. So, higher numbers are better. But make sure to clarify which unit is used in any RAM stick naming scheme. Manufacturers readily switch between MTps and Mhz. As a general rule of thumb, the MHz number of any RAM stick is its MTps number divided by two.
CAS latency or Column Address Strobe Latency is a much less talked about performance spec for RAM modules. In very simple terms, it’s a measure of how much time it takes for a RAM module to access specific data on its storage architecture. The longer it takes, the higher the CAS latency number.
Oft ignored CAS latency is an equally important spec for RAM performance, even more important than MTps number for some PC enthusiasts. A RAM module with lower MTps numbers can outperform another with higher MTps if its CAS latency is low enough. So CAS latency is an inverse of MTps – the smaller the number, the better.
Still, except you’re really concerned about performance, I’d leave CAS latency to the geeks. It’s hard to spot since many manufacturers don’t bother starting it, and for most consumer-grade RAM modules, the CAS latency numbers will be in and around a particular range. Are you a geek? You can find the CAS latency number on labelling strips of RAM modules (the first number group) or in reviews where they were tested thoroughly.
How many RAM slots are enough?
Most modern-day not-extremely-low-end PCs come with at least two RAM slots; that’s the port where the RAM stick inserts to communicate with other PC components. Having an extra free RAM slot on your PC build is essential if you plan to upgrade your RAM capacity. Some consumer-grade PCs might ship with up to four slots, but that’s rare, and as far as upgrades go, the single free slot in a 2-slot PC should be enough.
What you want to avoid is buying a laptop with just one RAM slot. Such a setup will force you to replace and bin your old RAM stick for an entirely new one if you ever decide to upgrade.
Figuring out what RAM setup to go with when shopping for a PC or laptop is a fairly straightforward endeavor.
First, identify your needs. Are you an everyday user who simply watches movies, surfs the web, streams and maybe does some writing?
Are you the moderate user who does some gaming every once in a while, or maybe you do some lightweight photo editing or graphic design.
Are you the heavy user with performance-intensive apps like MAYA 3D or Adobe After effects on your applist?
Your needs determine what RAM setup you should go with.
Everyday user, 6GB is the ideal threshold. You can dip down to 4GB, but a PC with a 4GB RAM setup might struggle when you over multitask.
Moderate user, gun for an 8GB RAM setup. That should be enough to handle all the performance hard work you throw at it.
Pro user, 16GB of RAM should be the minimum threshold. You can go up from here, but except you’re particular about top-tier performance, 16GB should be more than enough.