How to Choose RAM for a Gaming PC

RAM is a type of memory that your computer uses to store and quickly access files and apps. It is called random access memory because the computer can access it in any order, while other types of storage (like hard drives) require you to move through or search each file sequentially.

RAM also allows multiple programs and threads to run at once. Games often need more RAM than recommended for the operating system (OS) for real-time performance. This means having enough RAM is critical for improving both responsiveness and frame rates.

Each time you open an app or file stored on your hard drive, the data must be loaded from the disk into RAM. Conversely, when you close an app running from RAM, any changes are written back to the hard drive. The more RAM your system has, the less it has to rely on virtual memory (a part of the hard drive that is used as additional RAM) or swapping (moving content back and forth between RAM and virtual memory).

How Does RAM Work?

The data stored in RAM is lost as soon as the system powers down. The CPU and other components use virtual memory to prevent data loss and speed up the computer, also stored on a disk (typically a hard drive).

Whether it’s a game or not, Windows first moves any files associated with that program into the RAM when you start an app. This way, when you use that app, Windows can access it in RAM without searching for it on the hard drive every time. For example, if you’re gaming in full-screen mode and alt-tab out to check your email or IM window, anything outside of your game’s window will be moved from RAM to virtual memory instead.

What RAM Is Compatible with Your Motherboard?

Types of RAM
Types of RAM (Image credit: intel)

Compatibility is the first thing you need to check when buying RAM. Your motherboard must support the type of RAM you’re selecting (DDR3, DDR4) and how much memory it can handle (the maximum amount, whether that’s 32GB or 16GB).

The next thing to look into is your processor. While most CPUs today can work with faster RAM, they do so at the expense of compatibility with other components in your system. For example, using faster RAM than what is recommended by Intel will not damage your CPU - but doing so will force the computer to run only compatible motherboards and limit your choices for upgrading later on. The speeds of both the memory modules and their timing are critical factors in determining compatible systems with specific CPUs.

Module Type

Memory Modules come in either single inline memory modules (SIMMs), dual inline memory modules (DIMMs), or small outline dual inline memory modules (SO-DIMMs). The physical size of each module is important for compatibility with different motherboards and systems. For example, SO-DIMMs are often not compatible with older computers that use SIMMs or DIMMs.

Motherboards use one type of memory technology exclusively, while others are more flexible. For example, DDR2 compatible motherboards can use either DDR2 or DDR3 RAM, but not the other way around.


Your motherboard has a specific number of memory slots, depending on its model. It needs to have the same type and number of memory modules installed for your computer to work correctly. The sockets on your motherboard for DDR4 RAM are slightly different from those used by older SDRAM and DDR3 motherboards.

DDR4 SDRAM and DDR3 RAM modules have different shapes and numbers of pins, so they can’t be used in the same memory slot. Make sure to check the type of RAM supported by your motherboard before buying it.

If you’re using your older DDR3 RAM with a new motherboard, you shouldn’t have any problems, but the computer will POST (power-on self-test) at reduced speeds.

SO-DIMM memory modules have the exact physical dimensions as those used for DDR3, but they’re not compatible with newer motherboards even if they fit in the DIMM slots. Be careful when buying RAM for a new computer or upgrading your existing one; read up on what type of RAM is compatible with your motherboard.

Form Factor

Memory modules, especially those for desktops, come in various form factors. These may include:

  • DIMM: an older type of memory module used by early Intel models and low-cost PCs. The pins on a DIMM are usually spaced at 1/8" (0.15cm). Using a DIMM with a newer motherboard will work –but not as fast as the system can handle because of the smaller connector.

  • SO-DIMM: a popular format for laptops that uses a smaller number of pins spaced closer together than those on a DIMM. You can install SO-DIMMs into desktop computers, but they won't always work correctly due to incompatible voltages.

Important RAM Specs to

Power of RAM
Power of RAM (Image credit: intel)

When choosing RAM for your computer, you need to look into four critical specs: speed, CAS latency (CL), voltage, and capacity. The lower the latency, the faster a memory module is. In other words, low-latency modules are those with CL ratings of 7 or less.

  • Speed: This is also called the clock speed or memory clock, measured in MHz. You should aim for high speeds only if your motherboard supports DDR4 at frequencies of over 2133MHz - otherwise, choose a lower speed so you can use faster modules with other components in your computer.

  • CAS latency: This is also known as CL, and it indicates how many clock cycles a module takes to complete a single data transfer. Lower latency means the memory is faster, and you'll notice this mostly in computer games and other video or image editing software.

  • Voltage: The required voltage also depends on the type of memory modules you intend to use. For older models, the standard voltage is 1.5V or 1.35V for DDR3. Modern GDDR5 uses 1.2V, while DDR4 needs around 1.2-1.35V, depending on the clock speed of each module.

  • Capacity: Memory sticks are available in various capacities to suit your needs. If you're upgrading an existing system, go for double the ability so you can install more memory immediately instead of having to swap out single modules later on.

How Much RAM Do I Need for Gaming?

It’s hard to determine exactly how much RAM you need for gaming because it depends on other components in your computer. If you have an older model, you should first upgrade your GPU before looking into RAM.

  • Modern games: You can get away with 8GB of DDR4 or even less if you use integrated graphics (shared memory that's part of the CPU), but 16GB is recommended if you want to stream videos while playing without lagging. It may also be necessary to use multiple programs simultaneously, such as a game launcher and voice chat software.

  • Ultra settings: For demanding games like Battlefield 1 or Crysis 3, consider 32GB of DDR4 (or more), so you can load all the textures at ultra settings without worrying about running out of memory.

  • Gaming in virtual reality: If you use your computer for VR games, get at least 32GB so you can run the game and any other programs in parallel without lagging. 64GB is recommended if you want to stream 4K videos while playing.

  • Pro Gamers: To play competitively or do high-level photo editing, aim for 128GB or even more when using DDR4 modules with standard voltage. High frequencies are also ideal for pro gamers, but they're usually costlier than lower speeds that work just as well.

What RAM Speed Do I Need?

Your computer’s RAM speed depends on what it can handle and how fast your other components are. If you have a high-end GPU, choose modules with higher speeds for better performance.

The balance between speed and capacity that’s best for you depends on the type of games you play and what kind of computer you have. If your motherboard supports DDR4 speeds of over 2133MHz, go for faster modules to take full advantage of the slots in your case.

  • Less than 1600 MHz: Don't bother with this unless your system uses SO-DIMMs instead of DIMMs because they can't handle high frequencies. If you're upgrading an older model by installing a new GPU, the old memory will probably be too slow for demanding games even if your CPU is fast enough.

  • Between 1800 and 2400 MHz: This speed range is ideal if you want to save money without sacrificing much in terms of performance, mainly since most RAM modules are sold at speeds of 2400MHz or more.

  • Between 2800 and 3200 MHz: If you're looking to build a high-end rig, get modules with these speeds for the best balance between speed and capacity. You'll need fast GPUs like RTX 2080 or GTX 1080 Ti along with CPUs that support high frequencies if you want to take full advantage of faster RAM.

  • More than 3600 MHz: Aim for this range only if you have an AMD Ryzen Threadripper CPU since they can handle frequencies above 3600MHz. Also, buy GDDR6 memory, not DDR4, because it's faster and uses less power (1.35V or 1). For other types of computers, stick to lower speeds so your computer's other components can keep up.

What Is Dual-Channel RAM?

Styles RAM
Styles RAM (Image credit: intel)

Dual-channel RAM uses two sticks instead of one, which lets your computer load data faster. To use it, you must install matching modules in the appropriate slots on your motherboard (usually colored blue and white). RAM modules are usually labeled with the colors of their slots, so you can avoid mismatching them.

Dual-channel is more effective than single- or triple-channel RAM if your motherboard supports it, but its potential depends on what kind of sticks you buy and how many of them you put in your computer. Generally, buying more RAM decreases performance because it increases bottlenecks for data to pass through during heavy workloads. Also, don’t mix multiple types of memory because this usually slows down speed instead of improving it.

Memory Timings

The numbers for RAM timings that we mentioned earlier indicate how long it takes before each memory chip can respond to a command. Higher frequencies and lower latencies usually go together, but the best combinations vary depending on what kind of computer you have and what types of games you play.

Overclocking RAM

 If your CPU and GPU allow overclocking, you may be able to increase the speed of your memory without having to buy faster modules. However, this may not work out well if your motherboard doesn’t support overclocking or if it runs too hot when the chips are pushed to their limits.

Aesthetics and Cooling

For looks, choose modules in neutral colors like black or gray instead of red or white if they don’t cost too much more. For cooling, look for low-profile memory that doesn’t block the airflow of your case or laptop.

What Type of RAM Is Right for Your Gaming PC?

Before you buy new RAM, make sure your computer can support it. For desktops, this usually involves checking what kinds of slots are available in addition to how much each memory type costs. For laptops, the number of supported modules is limited by the size of their SO-DIMM slots.


To sum up, when choosing RAM for a gaming PC you should consider:

  • How much RAM do I need?

  • What speeds should the modules have?

  • What kind of RAM is best for my computer?

  • Do I need low profile or non-stick memory to avoid blocking the airflow in my case or laptop?

If you follow these tips, you can upgrade your system without having to worry about what type of memory to buy. In general, faster speeds and lower latencies go hand in hand but other factors affect performance as well. If you want the best possible experience from your games, make sure those components are right up there with all other kinds of hardware involved in pushing data through your system. If they’re not, your GPU and CPU won’t be able to push the pixels fast enough for you to enjoy the game.