CPU vs. RAM: Understanding The Differences

For those who are just diving into the process of buying or building a computer, the vast number of different parts can seem practically impossible to keep straight. There's just so much stuff to learn about! One key difference that can sometimes trip up computer builders and buyers is the difference between a CPU and RAM.

These two components serve very different purposes, but they're equally critical in giving you a functional PC with the performance you need. Once you understand the differences, you'll be better equipped to make the right choices about these critical parts — so let's get started by exploring how they work!

CPU vs. RAM: Basic Differences

The most fundamental difference between CPU and RAM comes down to function, and it's right there in the names of both devices:

• A central processing unit (CPU) is a processor. Basically, it's a type of microchip that executes the commands you give it and relays your instructions to all the various components of your computer. The CPU is sometimes referred to as the computer's “brain” because it handles the complex hardware and software instructions that allow your computer to do what it does.
• Random access memory (RAM) is a type of memory. Its job is to provide quick access to the files your computer is currently using, whether they're program files for your operating system or media files you're viewing. You can think of RAM as the “work surface” of your computer, where it keeps the essential tools for the current task close at hand.

As you can see, RAM memory and CPU are something of an apples-and-oranges comparison: two important components with very different functions. However, that doesn't mean they don't work together! In fact, understanding the way the CPU and RAM interact is key to understanding both components.

How Your CPU and RAM Work Together

Your CPU and RAM might as well be best friends — or at least close work buddies, considering how much they depend on each other. In fact, even your operating system (such as Windows or macOS) has to load its essential files into RAM before it can perform basic tasks such as loading your desktop or launching other programs.

Thus, from the moment you turn your computer on, your CPU is reading and writing data on your RAM almost constantly. Millions of these read-write cycles per second allow you to do everything from typing characters on Word to loading graphics assets in a game. The more of these cycles your RAM and CPU can complete, the faster its performance will be.

The size of a computer's RAM modules also has a significant effect on CPU performance. When RAM gets full (because you have a lot of applications open at once, for example), the CPU has trouble clearing enough space for the files it needs. Your system might move some of the files to a temporary memory space known as a page or swap file, and your general performance might start to slow down if things get really cramped. That's why it's important to know how much RAM you need for your intended tasks, such as gaming, creative projects, or software development.

CPU vs. RAM: Which Is More Important?

This isn't an either/or decision — every PC needs both! Both your RAM and your CPU are 100 percent must-have components for your PC, and furthermore, their specs have a significant effect on your PC's performance.

However, there's still the question of where your money is best spent. If you're struggling with whether to prioritize CPU or RAM in the computer you buy or build, here are a few pointers to keep in mind:

• Because the CPU plays such a critical role in the operations of the entire machine, a fast and capable CPU is one of the highest-priority parts to look at when evaluating a computer's specs. (Gamers tend to lean on the graphics card more, but for general use, CPU is usually the top dog.)
• While you definitely shouldn't skimp on RAM, it's also rarely at the top of users' priority lists. For the majority of computer users, a standard 16GB RAM kit will give you more than enough memory for productivity apps, web browsing, creative software, and most gaming. That said, 32GB is increasingly common for users who want high-performance PCs, and it will help future-proof your computer.
• CPUs are more complex and more difficult to manufacture than RAM, so pound-for-pound, they'll almost always cost more to begin with. Accordingly, you'll usually want to budget more for your CPU than your RAM if you're buying part-by-part.
• Make sure both your CPU and RAM are both up to the level of performance you want. Pairing a state-of-the-art CPU with 8GB RAM, or a high-end 32GB RAM kit with an older budget CPU, will result in a performance “bottleneck” in which one component prevents the other from operating at full capacity.

Motherboard Compatibility for CPUs and RAM

CPUs and RAM have another thing in common: Both plug directly into a computer's motherboard, which means both also need to be compatible with the motherboard's architecture. This isn't too hard to determine, but it does mean you need to pay attention to compatibility specs if you're building a PC, or if you're replacing your CPU and/or RAM.

Every motherboard is designed for compatibility with CPUs from one of the two major manufacturers: AMD or Intel. You can't put an AMD CPU in an Intel motherboard or vice versa, so you'll need to purchase a motherboard according to which brand you plan to use. The CPU and motherboard also need to use the same chipset and socket type. All of these compatibility challenges are why lots of PC builders choose to go with a pre-selected CPU and motherboard combo.

RAM compatibility is a little bit simpler. First, you'll need to look at whether the motherboard supports DDR4 or DDR5 RAM. In addition, look at the maximum amount of RAM it can support. It's a good idea to get a board with capacity for at least 32GB, even if you're not using that much RAM now. Finally, check the maximum RAM clock speeds that your motherboard can support, as some RAM modules may have faster top speeds than your board can make use of.

Overclocking Your CPU and RAM

Another thing that CPUs and RAM have in common is overclocking: a technique for extracting more power and performance from PC components by setting them to run faster than their factory settings. (This applies only to PCs. Macs generally can't be overclocked.) Most PC users don't need to mess with overclocking, but it can be a relevant factor in the buying process for anyone who wants to get the most from their PC.

CPU Overclocking

The CPU is the most commonly overclocked component in PCs. Basically, since the manufacturing process of CPUs is somewhat unpredictable, many models come factory set for a minimum guaranteed speed — but, if you won the so-called “silicon lottery,” yours might actually be capable of much faster speeds. If you have an unlocked CPU (and your motherboard supports overclocking), you can change your CPU's clock multiplier and voltage in the BIOS and explore just how fast it can go.

RAM Overclocking

Overclocking your RAM is also common among PC performance enthusiasts, especially since most RAM isn't configured off the shelf to run at its rated maximum speed. You can overclock it straight from your BIOS, but you'll need to learn about complex topics like RAM timings while being careful not to make changes that can harm your system. However, high-quality RAM often includes a technology called Extreme Memory Profiles (XMP). These profiles make it easy to switch to a higher RAM speed while maintaining a stable system.

Does all this overclocking stuff sound unnecessarily complex? Then don't worry about it! Again, for the majority of users, overclocking is by no means required for good PC performance. The point is that if you do intend to overclock your CPU and/or RAM, you'll want to be sure to look at the specs of your components and verify that they support overclocking.

Anytime you need us, Micro Center's PC experts are happy to help! We're game to explain CPUs, RAM, graphics cards, or any other PC parts, and to make practical recommendations that keep your budget in mind.

Ready to buy? Check out our wide variety of deals on CPUs and RAM memory, and remember that we also offer installation and PC building services! Or, put together your dream PC in our PC builder tool. Then, order online and pick it up in your local store.