Single Channel vs Dual Channel RAM [+Performance Compared]

CG Director Author Christopher Harperby Christopher Harper   /  Updated 

In the battle of Single Channel vs Dual Channel RAM, which comes out on top?

More importantly, why does it come out on top, and how does it actually impact your end-user experience?

I’ll be walking you through all of that in this article to the best of my ability, as well as closely-related questions you may want to know.

For now, let’s just get into it.

A Brief on RAM and RAM Channels

So RAM, or Random Access Memory, serves as a real-time cache for the applications running on your CPU.

VRAM, or Video Random Access memory, does the same for GPUs.

The main form that RAM comes in is DDR RAM or Double Data Rate RAM. Technically, Double Data Rate Synchronous Random Access Memory, or DDR SDRAM. I’m never typing that again.

SDR vs DDR

However, the secrets to DDR (SD)RAM are actually tied into that naming. Especially that “Synchronous” part.

The big advertised boon of DDR RAM is its ability to sync up with similar models of itself in order to achieve higher speeds and throughput– at least in theory.

There’s actually quite a bit that goes into that, which I’ll be discussing as we progress further into the comparison.

For now, let’s define Single Channel and Dual Channel RAM.

Single Channel RAM describes any RAM configuration where you only have a single RAM Stick- even if you have a RAM stick capable of more, it will be restricted to Single Channel without a separate RAM stick to be all synchronous with.

However, it also describes how that single RAM stick is being run- in a Single-Channel mode instead of the Dual Channel DDR RAM is supposedly made for.

Single Channel vs Dual Channel Configuration

Two identical RAM sticks mounted properly will run in a Dual Channel configuration, which is said to increase RAM transfer speed twofold.

More on how that actually works in the “Speed & Throughput” section!

Single Channel vs Dual Channel RAM: Cost for Capacity

This is the first and most obvious basis with which to compare Single Channel and Dual Channel RAM.

In raw materials, Dual Channel RAM will always be more expensive to produce, since it requires two identical sticks rather than just one.

That being said, if you started with a Single Channel RAM stick and later added an identical one, you would then be running in Dual Channel- so it’s not like a permanent choice between one or the other (Although buying RAM at different times and not in a KIT complicates things in terms of compatibility).

That being said, the cost for capacity usually leans in favor of single-channel kits, even if not by very much.

The winner is Single Channel, by a thin margin.

Single Channel vs Dual Channel RAM: Speed & Throughput

It’s important to make a distinction between marketing and what is actually happening.

As helpfully explained in extensive detail by my fellow writer Jerry James in his own article, DDR RAM isn’t actually doubling its effective speed when run in Dual Channel, despite popular belief stating otherwise.

Single Channel vs Dual Channel bandwidht

This is because Dual Channel doesn’t actually double frequency, even though the advertised Megahertz ends up being that!

A Dual Channel DDR4 kit rated for 4200 MHz actually runs at 2100 MHz on both sticks, but working together they’re able to output a data rate of about 4200 Megatransfers (MT/s rather than MHz) per second.

They aren’t actually running at 4200 MHz to do this, even if the advertising claims otherwise.

The reasons why are a little complicated (do read that article above to find out), but important to keep in mind- your RAM will still run at basically the same frequency in Single-Channel, it’ll just have its data rate cut roughly in half.

So, Dual Channel wins- at least on paper.

Well, it does just kind of win, but it’s worth noting that the majority of applications you use probably don’t care if you’re using single or dual-channel RAM unless they are actually RAM speed or latency-constrained in some way.

This kind of stuff matters more for gamers and creative professionals than it does, say, casual users or office PC users.

If you’re interested in learning more about how your RAM speed can impact certain workloads, head to my RAM Frequency Guide!

Single Channel vs Dual Channel RAM: Gaming Performance

So, how do Single Channel and Dual Channel RAM configurations stack up in games?

Historically, not very much. Most older games simply didn’t need the increased bandwidth offered by Dual Channel RAM, and this failed to use it effectively.

In recent years, however, this has started to change with the rise of modern game engines.

Modern game engines are capable of taking a PC’s resources much more thoroughly and intensively, scaling across multiple cores and eager for bandwidth wherever they can get it. And with multiple CPU Cores wanting to access your RAM, multiple channels come in handy.

This also makes modern games more sensitive to unexpected bottlenecks than old games used to be, and yes- this manifests in a tangible decrease in performance for Single Channel users.

Single Channel Benchmark

Image Credit: Hardware Times’ Single Channel Benchmark

 

Dual Channel Benchmark

Image Credit: Hardware Times’ Dual Channel Benchmark

As documented by Areej writing for Hardware Times, a number of modern games simply perform far worse in average FPS with a Single Channel configuration.

Even if the games seem to be running at around the same average, the Single Channel configurations consistently saw much worse 1% and 0.1% lows, which means that drops in framerate were frequent and severe.

Dual-Channel would improve these numbers massively, even in scenarios where the averages did not approve.

Dual Channel benchmark for Assassins' Creed Origins

Image Credit: Hardware Times

So at least for gaming, it would seem that Dual Channel RAM provides more consistent baseline performance overall, but only provides an average FPS improvement in specific titles.

The specific titles that seem reliant on Dual Channel configurations will heavily favor them for average FPS, though.

Some games also seemed to care more about RAM speed than configuration, making it possible for a Single-Channel 3600 MHz RAM stick to beat slower Dual Channel competitors in certain scenarios.

Single Channel vs Dual Channel RAM: Rendering and Productivity Performance

So, what about rendering and productivity performance?

Truthfully, the results can massively vary- from almost no difference at all to major differences with certain workloads.

As tested by GamersNexus back in 2014, though, there are times when you can see some minor benefits from switching to Dual Channel.

Single Channel vs Dual Channel RAM benchmark for Handbrake Transcoding Time

Image Credit: GamersNexus

Adobe AE CS5 FPS Single Channel vs Dual Channel RAM benchmark

Image Credit: GamersNexus

So it seems that for things like video encoding and real-time previews during video editing, upgrading to Dual Channel can give you a roughly 5-6% bump in your performance. You can’t necessarily expect this to carry across all workloads, though.

Now, this doesn’t mean that there isn’t value in improving your channel configuration in general- there probably is- but this also goes to show just how often changes to RAM won’t matter until it’s actively bottlenecking you.

In general, I would veer on the side of Dual Channel or higher for professional workloads, especially those involving managing lots of big files (video editing, conversion, etc) and running multi-core optimized workloads.

CPU Cores that have to access your RAM at the same time can do so through multiple channels. Two Cores at once through dual-channel, four cores at once through quad-channel, and so on.

Do note, that for quad Channel you’ll need a Motherboard that supports this. Just because you have 4 RAM Modules doesn’t mean they’ll run in quad-channel mode. The same is true for Hexa or Octa channel on higher-end Motherboards.

Single Channel vs Dual Channel RAM: Conclusion

Well, now you understand the difference between how Single Channel and Dual Channel RAM kits work.

Dual-Channel is pretty much always better, but having 1 instead of 2 RAM sticks isn’t the worst thing that can happen to you.

When picking RAM Modules, here’s a list of factors that’ll impact your PC’s performance, from most important to least:

  1. Capacity (in GBytes, higher is better)
  2. Matching RAM (Buy RAM in a KIT)
  3. Channels (Single, Dual, Quad, Hexa, Octa, Higher is better)
  4. Frequency (The higher, the better)
  5. Latency (e.g., CAS Latency, the lower, the better)
  6. Ranks (Single, Dual, Quad Ranks, depending on your use case, usually higher is better)
  7. Brand (e.g., Corsair, G.Skill)
  8. Sides (Double / Single Sided, depends on your use case, single is generally better for lower temps)

FAQ

What should RAM Frequency be set to?

Probably whatever number is on the box, through enabling XMP or your AMD equivalent in your motherboard’s BIOs.

If you don’t know what any of that means, XMP refers to Xtreme Memory Profiles.

These store clock rates for the memory onboard and are activated through the BIOs, enabling the RAM’s rated speed…unless you have to tweak it, which you might.

A good place to start with XMP profiles would be Jerry’s Guide to Setting XMP Profiles!

Is DDR5 Better Than DDR4 RAM?

Uh yes and no.

As DDR5 tech evolves, it may become a more compelling option over DDR4, especially as CAS Latencies are reduced and speeds continue to increase.

However, explained by Jerry, right now the performance gap really doesn’t justify the price gap, and it probably won’t for some time.

If you want some high-performance RAM that actually might be worth the money- especially if you’re using a Ryzen CPU and are a gamer or overclocker- consider checking out some Samsung B-Die RAM kits.

B-Dies offer superb low latency and pretty good speeds, making them an ideal companion to a gamer or overclocker’s PC build. It may be limited to DDR4, but the improvements in latency will give you better results for the money, especially in games.

Over to You

And that’s it, at least for now! I hope that this article helped you come to a better understanding of what Single Channel and Dual Channel are, and how you can expect them to impact your experience.

Leave a comment below and let me know if you have any lingering questions, or head to the forums with anything else you might need!

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Christopher Harper - post author

I have been a passionate devotee to technology since the age of 3, and to writing since before I even finished high school.

These passions have since combined into a living in my adulthood and have made writing about PC Hardware very satisfying.

If you need any assistance, leave a comment below: it’s what I’m here for.

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