If you’re looking to build a gaming PC or update your current one, you might need to decide whether you want single channel, dual channel, or quad channel memory. Picking the right RAM means not just considering its speed and capacity, but also comparing it to your motherboard and CPU’s memory channel support.
If you want the cheapest option, this will be to opt for one memory stick in one DIMM slot for single channel RAM. But dual channel memory—two sticks in two slots running on different channels of the memory bus—can give a performance boost for only a little extra money.
You can also opt for four or more RAM sticks running across quad channels, but most CPUs and motherboards don’t support this. And most PC users and gamers won’t utilize four channels of memory throughput, meaning quad channel memory is usually reserved for niche use cases.
In this guide, we’ll look at what single channel, dual channel, and quad channel RAM is, and which memory setup is best for your productivity and PC gaming needs.
Also Read: How to Choose RAM: 4 Things to Consider
What is Computer Memory (RAM)?
RAM (Random Access Memory) acts as your computer’s short-term memory. It’s volatile memory, meaning it requires constant power to store data, and whenever your PC turns off RAM data is lost. RAM, however, is quick—your CPU can store and access it very quickly.
Because RAM is fast and volatile, it usually stores data that your CPU expects it will often need quick access to. For instance, if there’s some code that your Operating System, a game, or an application uses frequently, this code will likely be stored as data in RAM so that the CPU can access it quickly.
Physically, RAM is found in the form of DIMMs (Dual Inline Memory Modules), which are sticks that have memory chips on each side. They slot into your motherboard’s memory slots, which are usually right next to the CPU slot.
What’s the Difference Between Single and Dual Channel RAM?
Think of a memory channel as a single route (technically, a “memory bus”) for your RAM data to travel down—from RAM, through your motherboard, and into your CPU’s memory controller (or vice versa). If your RAM is single channel, all data is flowing along a single memory bus that can handle 64 bits of data at once. If it’s dual channel RAM, the data is flowing along two 64-bit routes at the same time.
Most modern gaming motherboards come with dual-channel mode support. Similarly, most modern CPUs support dual-channel memory.
To use two memory channels, you need to put a single stick (one DIMM) into a motherboard RAM slot, and another single stick into a motherboard RAM slot that uses a different channel. Your motherboard manual should tell you which slots these are. Usually, however, these will be the second and fourth slots, counting from left to right away from the CPU.
If your motherboard and CPU support dual channel RAM, you need to ensure the RAM you buy will work in dual channel, too. To maximize your chances of it working across two channels, the two DIMMS should be rated at the same capacity, speed, and latency. The easiest way to ensure this is to buy a two-pack of identical RAM sticks.
What About Quad Channel RAM?
Most motherboards support single channel or dual channel ram implementations, but some support four memory channels. In such quad channel systems, we can install four or more RAM sticks in different slots that allow data to travel across four different channels.
However, most motherboards and CPUs don’t support quad channel memory, and it’s mainly reserved for server systems. This isn’t a problem, though, because there’s little benefit to quad channel memory over dual channel memory for the average PC user or gamer.
Why Use Dual Channel or Quad Channel Memory?
The main reason to use dual channel RAM or quad channel RAM is to increase your memory bandwidth.
Each channel that data travels through can only transmit a certain maximum amount of data, in the same way that a pipe can only transmit a certain amount of water thanks to the pipe’s width.
Using two memory channels is like using a second pipe, doubling the amount of data that can be transferred each second. (RAM speed also plays a part in this, of course—just like the speed of water traveling through a pipe affects the amount of water it can transmit each second.)
Using a dual-channel configuration should provide double the maximum throughput to a single-channel configuration. And using a quad-channel configuration should provide quadruple the maximum throughput to single channel memory.
Most systems and applications, however, won’t make use of quad channel bandwidth, making dual channel memory a sweet spot before diminishing returns.
Practically speaking, more bandwidth—such as when going from single channel to dual channel RAM—should mean higher framerates and faster Operating System and application performance. But this depends on how much bandwidth the software in question can use. Sometimes, a single channel is enough.
Benchmarks: Single Channel vs Dual Channel RAM
To compare single vs dual channel RAM, we took our 2x16GB (32GB) DDR4 RAM sticks and benchmarked them in single channel configuration (B+B) as well as dual channel configuration (A+B).
Test Bench Specs
|Motherboard||Gigabyte Z690 UD DRR4|
|Graphics card||MSI GeForce RTX 3060 Ti GAMING X 8G LHR|
|CPU||Intel Core i5 12600KF|
|RAM||32GB (2x16GB) Corsair Vengeance LPX (DDR4, 3600MHz, C18)|
|Storage||ADATA XPG SX8200 Pro 1TB (NVMe M.2 SSD)|
|PSU||EVGA SuperNOVA 650W G2 80+ GOLD|
In the three games we tested (GTA V, Shadow of the Tomb Raider, and Metro Exodus), there was an overall framerate increase of 9.6% when moving from single channel to dual channel memory.
As you can see, however, there was little difference in Metro Exodus—probably because this game is very GPU-bound. Memory speed and bandwidth typically play a bigger part in the performance of CPU-bound games.
Also Read: How Much Does RAM Affect FPS in Games?
Performance differences will vary depending on the game and how well it utilizes wider memory bandwidths. Results may also vary depending on your total memory capacity.
Overall, though, with dual channel memory, you can expect average framerates roughly 10% higher than with single channel memory.
We tested single and dual channel RAM in PassMark and GeekBench. PassMark gives us a Memory Mark, while GeekBench only gives us two CPU scores.
As we can see, PassMark shows a significantly higher score when we run our 32GB DDR4 RAM in dual channel configuration. Our dual channel memory scored 19.4% higher than our single channel memory.
While GeekBench only calculates our CPU score, this isn’t irrelevant. This is because many CPU benchmarks like GeekBench require extensive use of RAM—after all, RAM is where the CPU draws its data from.
Plus, getting a CPU performance benchmark result helps because memory benchmarks alone don’t tell us too much, as they might not translate to real-world performance in applications. Memory-aided CPU performance, however, is much more likely to translate to real-world performance.
We see that while GeekBench only shows a 4.3% increase in performance in the single-core test, it shows a whopping 36% performance increase in the multi-core test. This implies that applications that make good use of your CPU’s different cores will benefit greatly from running your RAM in a dual channel rather than single channel configuration.
With productivity, just as with games, however, performance differences will be application-dependent, because it depends how well the application uses extra memory bandwidth.
Dual Channel vs Quad Channel RAM
If you’re lucky enough to own four identical sticks of RAM, and a motherboard and CPU capable of running memory in quad channel configuration, you might as well do so. If, however, you’re deciding whether to upgrade to such a system, it might be best to hold off.
While we couldn’t test dual vs quad channel memory ourselves, we can look to other online benchmark comparisons such as those from PC World to get a good idea of whether upgrading to quad channel memory is worth it.
What we see from PC World’s benchmarks is that while, yes, a memory bandwidth benchmark recognizes the extra bandwidth, in real-world applications such as Handbrake, PCMark 8 Creative, WINRAR, and 7-Zip, there was almost no performance difference between systems with dual and quad channel memory.
Ditto for gaming. In fact, in one benchmark (for Bioshock Infinite), dual channel memory actually outperformed quad channel memory.
So, what exactly is quad channel memory for if it doesn’t improve performance in these productivity applications and games? Primarily, for servers. Unless you’re putting together a dedicated server rig, there’s little benefit to using quad channel memory over dual channel memory.
Can Your Motherboard and CPU Use Dual or Quad Channel Memory?
Most modern motherboards and CPUs support dual channel memory.
If you’re using one of the best CPUs for gaming that isn’t more than a few years old, whether budget or high-end, it should support dual channel memory. You can check the CPU specifications on the manufacturer’s website to make sure, though.
Similarly, you can check your motherboard specifications on its manufacturer’s website to see whether it supports dual channel memory. If it’s got four RAM slots, it probably supports it, as these slots will probably be in an AABB channel configuration.
If your motherboard only has two RAM slots, this doesn’t necessarily mean that it doesn’t support dual channel memory, though. Small form factor motherboards, for example, might cut out two RAM slots to save space, but still support dual channel RAM in AB configuration.
When it comes to quad channel memory, however, the situation isn’t as promising. To run quad channel memory, you’ll probably have to look towards HPC (high performance computing) or server CPUs and motherboards, such as AMD’s Threadripper and Epyc CPUs and their corresponding motherboards, or Intel’s Xeon or i9 Extreme Edition CPUs and corresponding motherboards.
Should You Use Single Channel, Dual Channel, or Quad Channel Memory?
If you’re a PC gamer, you should probably opt for dual channel memory if possible.
You don’t need to spend too much more to get a two identical RAM sticks—especially if you’re opting for a 2x4GB or 2x8GB setup—and most CPUs and motherboards should support dual channel RAM. For this, you get about 10% better gaming performance, although this will depend on the game in question.
Similarly, you should notice an increase in performance using many productivity apps—especially those that make good use of multiple CPU cores. Even your Operating System should perform a little better with dual channel memory than with single channel memory.
Quad channel memory, however, isn’t worth it for most gamers. Most motherboard and CPU combos don’t support it at all, and most games and applications won’t noticeably benefit from memory running across four channels. They simply don’t use all that extra bandwidth.
This doesn’t mean that you can’t use four RAM sticks, however. If you have a motherboard with four RAM slots but only two memory channels, you can still use four RAM sticks, but these will run across two 64-bit memory bus channels.
For the vast majority of gamers and PC users, though—even creative professionals and productivity users—two RAM sticks running in dual channel configuration will be ideal, and will hit the price-performance sweet spot.