Learn what RAM is, the difference between DDR4, SDRAM & DIMM, and how RAM can impact the gaming experience.
RAM (random access memory) is a key component in any gaming PC. Adding more RAM can boost system responsiveness and improve frame rates when compared to systems with less memory.
Read on to find out how RAM works, how to find compatible modules, and how much memory you really need for gaming.
How Does RAM Work?
RAM’s purpose is to store the short term data that a PC requires to properly operate. But unlike a hard disc drive or SSD (solid-state drive), which store data indefinitely, RAM resets every time the system is rebooted.
RAM is “volatile memory,” meaning it only stores data when it has power, as opposed to a “non-volatile” HDD or SSD. Programs are loaded into RAM temporarily while in use, but reside on a storage drive permanently (until deleted).
Computers need quick access to temporary data in order to run programs or execute tasks. Modern PC games, for example, need to rapidly retrieve art assets. Games read and write data to RAM because it’s orders of magnitudes faster than accessing data on a storage device.
What RAM Is Compatible with Your Motherboard?
Before you start thinking about RAM capacity and frequency, you should ensure RAM is compatible with your motherboard and processor. The wrong type of modules simply won’t work, while RAM with the wrong specs for your PC can underperform.
RAM comes in sticks, or memory modules, that snap into the memory slots on the motherboard. RAM that’s incompatible with your system either won’t fit, or won’t function properly.
Motherboards in modern computers support DDR4 RAM. DDR4 shouldn’t be confused with DDR3, the previous generation of SDRAM. They’re not interchangeable, and you can’t replace (for example) 8GB of DDR3 with 16GB of DDR4.
DDR4 and SDRAM
Computers use a type of RAM called SDRAM (Synchronous Dynamic Random Access Memory). “Synchronous” DRAM is synchronized with the frequency of the processor. SDRAM has improved over time, offering benefits like lower power consumption, faster transfer rates, and more stable data transmission.
DDR4 SDRAM is the current standard for modern-day computers. DDR4 stands for “Double Data Rate 4,” and is the fourth generation of DDR technology, which replaced SDR (Single Data Rate) SDRAM. DDR4 features faster data transfer rates, larger capacities, and lower voltages than the previous generation.
If you’re building a new PC or upgrading RAM in a relatively recent system, you’ll probably be dealing with the current standard of DDR4 SDRAM.
Why isn’t DDR4 backwards compatible? Because it has different timings (see below), voltage, and pin count, among other characteristics. To prevent accidental installation, the key notch on DDR4 modules is located after a different pin than DDR3 modules, ensuring it can’t slide into DDR3 slots.
There are a few easy ways to find compatible memory. Check the documentation for your system or processor, run a system profiling utility, or use an online memory compatibility tool.
DIMM (Dual in-line memory module) sticks are larger RAM modules, designed for desktop motherboards.
SO-DIMM (small outline dual in-line memory module) are smaller modules made for laptops, Intel® NUC mini-PCs, and some Mini-ITX small form factor (SFF) motherboards.
Important RAM Specs
- Capacity: Measured in gigabytes (GB). The higher the capacity, the more data can be stored by applications. At higher capacities, more applications can run simultaneously, and games can store larger amounts of temporary data.
- Speed: Measured in megatransfers per second (MT/s), this is often also treated as the speed in megahertz (MHz), although it is a different measurement than clock speed. Higher speed ratings mean a faster response to read and write requests, and therefore improved performance.
How Much RAM Do I Need for Gaming?
It depends. Are you planning to play games in focused sessions, or do you stream and multitask?
For gaming, 8GB is considered the baseline for AAA titles. However, RAM demands are increasing. Red Dead Redemption 2, for example, recommends 12GB of RAM for optimal performance, while Half-Life: Alyx requires 12GB as a minimum. So, if you want enough overhead to keep playing new releases in the future, 16GB of RAM is recommended.
If you plan to do more than just gaming, consider 32GB. This gives you the freedom to live-stream, group-chat on Discord, and have YouTube or Twitch open in the background.
If you’ve got the budget and the need for more RAM (for 3D modeling or other professional applications), Windows 10 Home and the latest Intel® Core™ i9 processors support up to 128GB. Check “Max Memory Size” under your processor’s memory specifications.
What RAM Speed Do I Need?
Look for the right balance between capacity and speed. It’s likely that 32GB of slow RAM isn’t ideal, but neither is 4GB of fast RAM.
DDR4 RAM speeds begin at around 1600MHz, but these speeds are considered slow by today’s standards. The Intel® Core™ i9-10900 processor, for example, supports 2933MHz at stock specifications.
For gaming, there are advantages to running RAM with high-rated speeds. Although it won’t have as profound an effect as upgrading the processor or graphics card, faster RAM can improve game performance and frame rates.
Performance improvements vary from game to game: some see a noticeable boost, while others are barely impacted. It’s worth checking benchmarks for average frames-per-second to see if the upgrade is worth it.
In addition to improving the frame rate, faster RAM can improve frame times, or the steadiness of the frame rate. This will be represented as the 1% and 0.1% low values (averages of the slowest 1% and 0.1% of frames recorded) in the benchmarks.
Outside of frame rates, faster RAM can also improve other areas of a system’s performance, such as shortening boot times.
RAM is typically purchased in sets of two or four modules (for example, “2x16GB” or “4x8GB”). Before buying a kit, check to see how many memory slots your motherboard has.
Desktops typically have four slots, while laptops usually have two. Enthusiast-class PCs and workstations may have eight or more, while the number of slots on unique setups like NUCs and SFFs will vary.
If you’re planning on upgrading the RAM in a laptop, make sure the RAM is accessible and not soldered onto the motherboard. Some laptop RAM isn’t intended to be swapped out.
If you’re planning on upgrading a desktop, try to leave memory slots open for future expansion when possible. For instance, installing a 2x16GB kit instead of a 4x8GB kit on a desktop leaves you with two slots open for future upgrades.
To take advantage of the increased bandwidth provided by dual-channel RAM, it’s recommended to install at least one pair of RAM modules in symmetrical slots (usually color-coded). The modules must have the same capacity, and ideally the same speed: if the speeds don’t match, the module with the slower speed will set the pace.
What Is Dual-Channel RAM?
Many modern computers feature dual-channel memory. Dual-channel (or interleaved) mode allows the CPU’s memory controller to exchange data with RAM through two channels, reading and writing to two sticks of memory simultaneously. This increases the available bandwidth.
Dual-channel mode will be automatically enabled on most motherboards with only two DIMM slots. When using two sticks in a motherboard with four slots, however, the memory must be installed symmetrically to use the same channel. The slots are often color-coded, but may be either staggered or side-by-side. Check the motherboard documentation for more specific instructions.
For ideal performance, ensure every stick of memory has the same speed, capacity, and timings. Avoid mixing and matching different module specifications if possible.
RAM speed isn’t the only way to judge performance.
RAM timings are a measure of latency, or the delay before RAM can execute the commands it’s been given. Memory timings are given as a set of numbers, such as 16-18-18-36, which may be seen on the module’s factory sticker.
Each number corresponds to a specific test. The first number, for example, is CAS (Column Address Strobe) Latency—the number of clock cycles it takes for the memory module to return a set of data after a request from the memory controller.
Comparing RAM modules based on timings can be complicated. For instance, CAS Latency only states the total number of cycles; the duration of each cycle also matters when judging responsiveness. For example, DDR3 memory usually has a lower CAS Latency than DDR4, but performs worse due to its slower clock speed.
Memory timings aren’t usually a high priority consideration for a gaming PC. Timings are of interest to overclockers, who can manually lower timings in the BIOS, then test for stability. If successful, you can get better performance out of your existing RAM.
For most gaming PC users, RAM capacity and speed are the most important considerations.
If you’ve purchased high-performance RAM, overclocking can help you go beyond stock specifications. The easiest way to do this is through Intel® Extreme Memory Profile (Intel® XMP).
When an Intel® XMP profile is selected in the BIOS of a supported motherboard, it adjusts voltages, timings, and frequency to enhance performance. These predefined settings have been tested and certified for stability.
It’s also possible to tweak memory profiles on some motherboards, as well as fine-tune settings manually from the BIOS.
To get started, check out this in-depth guide on how to overclock RAM.
Aesthetics and Cooling
Memory heatsinks can make your setup look more attractive. However, they are often purely aesthetic.
RAM generates heat like any other component, but it doesn’t run very hot unless it’s operating at unusually high speeds. Feel free to skip the heatsink if you’re not seriously overclocking your RAM. However, as with any component, it’s always good to make sure your memory is exposed to proper airflow.
Memory modules with RGB lighting can also add an element of customization and can improve your system’s visual appeal. Just be sure that the RGB memory sticks you select are compatible with your specific motherboard brand.
What Type of RAM Is Right for Your Gaming PC?
Ultimately, how much RAM you need for gaming will depend on your budget and use case. Before making a purchase, make sure the RAM’s specifications align with your unique needs.
It’s important to balance RAM with the rest of your system’s components, as they will all play a role in determining the overall level of performance.
To learn more about balancing the components in your system, check out our guide to a balanced PC.