DDR3 1600 vs 1866 vs 2400 vs 2133 – 2023 Ultimate Comparison Guide

| Last Updated: January 16, 2023

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So you want to upgrade your RAM, but you’re not sure what the numbers attached to each stick of RAM mean? Don’t worry, we’ve got the specs you need.

You aren’t the only one wondering whether you’re getting the specs that you need for the right price. We’ve found the options that give you the best speed and we also picked out the frontrunners for those who want to consider higher cost and better performance.

Let’s get down to details.

TL;DR: DDR3 1600 vs 1866 vs 2133 vs 2400




Best for


  • Good value

  • Low power

  • Low latency
  • Not the fastest

Best for a subtle boost in processing for tasks like editing


  • Noticeable difference in speed

  • Good value

  • Low power
  • Not the fastest

Best for those looking for a noticeable boost in speeds for tasks and casual gaming


  • Low power

  • Good speed

  • Good bandwidth
  • More expensive

Best for those frequently carrying out video editing tasks or gaming


  • Fastest

  • Good bandwidth

  • Speed not affected by latency
  • Higher power

  • Expensive

Best for those with a bigger budget who want maximum speed for gaming or editing and programming tasks

Relevant Specs: DDR3 1600 vs 1866 vs 2133 vs 2400

You can get variations of types of each DDR that create the range in latency, which is why we’ve listed top and bottom figures here. We measure latency in column address strobe (CAS) latency (CL), row address strobe (RAS) to CAS delay (tRCD), and RAS precharge (tRP). 






800MHz or 1600MT/s

933⅓ MHz or 1866⅔MT/s

1066⅔MHz or 2133⅓MT/s 

1200MHz or 2400MT/s



8-8-8 to 11-11-11

10-10-10 to 13-13-13

11-11-11 to 14-14-14

11-11-11 to 16-16-16


Run at 1.5V

Run at 1.5V

Run at 1.5V

Run at 1.65V

Theoretical Bandwidth





DDR3 1600: What Is it Best For?

One reason you might choose DDR3 1600 if you value power over maximum speeds. Since you can run it at 1.5V, then it’ll be less demanding than a 1.65V RAM. More power creates more heat, and that can increase the wear and tear on the chip and your motherboard.

Photo credit: kingston.com

Another reason to opt for DDR3 1600 is the low latency numbers. The higher the clock speed, the better, which would put DDR3 at the bottom of the pile. It boasts low latency numbers, though, and those can come in handy in certain situations. If you’re looking to boost your RAM to see some small but significant improvements in processing tasks, this chip might suit you.

Just a little more speed and memory have been shown to improve creative tasks. If you’re using your PC for photo editing, graphic design, or other detail-oriented work, opting for a small boost through a DDR3 1600 could help. Your budget is something to take into consideration, particularly if you’re interested in getting the best value. DDR3 1600 will cost less but will deliver results if you frequently edit photos or videos, though these results might be slower than say 1866.

DDR3 1866: What is it Best For?

Just like 1600, the DDR3 1866 runs on 1.5V, which means it won’t consume a lot of power or add as much heat and wear as the DDR3 2400. If you’re looking to optimize your PC, then adding 8GB or 16GB of DDR3 can give you noticeable gains in performance. 

With the 14,900MB/s theoretical bandwidth, the DDR3 1866 is considered the sweet spot for upgrading your RAM. You’ll pay a little more than you would for the DDR3 1600, but you’ll also see processing times reduced.

Photo credit: pcguide.com

The primary place you’ll see an impact in is your regular computer tasks. The minor improvement you get with DDR3 1600 can be boosted by opting for a little more speed with the DDR3 1866. It will cut a few seconds off of loading applications, and you’ll see a faster pace overall when completing work on your PC.

If you’re a casual gamer, DDR3 1866 might make sense for you. As you move up in RAM speed, you’ll see better rendering and performance in your games. However, if gaming isn’t your only reason for upgrading your RAM, you can keep the low latency and don’t need to stretch your budget to anything higher than DDR3 1866.

DDR3 2133: What is it Best For?

DDR3 2133 is the fastest RAM in the list that still runs at 1.5V. As we’ve already mentioned, this is important for power usage but also looking after your equipment. Although the latency numbers jump up a little with this chip, the theoretical bandwidth and speed make up for that, so expect to see a better performance.

The cost of DDR3 2133 will probably be more expensive than its slower counterparts, DDR3 1600 and DDR3 1866. That means you should know that this chip delivers a noticeable difference and offers value for money in the performance improvement. 

If you’re building your own gaming PC, we recommend looking to spend that bit extra to get the 1066⅔MHz of the DDR3 2133. The DDR means “double data rate”, which is why you get two times the 1066⅔ speed, as two sets of data are being processed at that speed. 

That difference between the DDR 2133 and the two slower chips will help you make the most of the other parts that you’ve invested in. The idea is to get a decent result when gaming and the extra expense is worth it if you’re taking the time to build a PC. 

Gaming will be smoother.

DDR3 2400: What is it Best For?

We’ve mentioned several times that the extra voltage of the 16.5V DDR3 2400 is a downside of this chip. If you’ve taken that into account, or you aren’t worried about more heat, then you could consider the fastest RAM available in the DDR3 category.

The 19,200MB/s theoretical bandwidth and the 2400MT/s speed mean the slightly higher latency won’t be noticeable. This chip will deliver more speed than the others on this list, so the slightly higher voltage is the only downside. Budget will play a role, which is why it’s essential to consider whether you need that much speed.

If you’re a serious gamer, consider getting DDR3 2400. If you can find it for the right price, it will be an excellent way to improve performance through speed, especially if you play a lot of demanding games or games with high graphic requirements. Sticking to at least 8GB or 16GB memory as best as you’ll need that as much as speed. If the extra power bothers you, there’s the option to undervolt and underclock it.

DDR3 1600 vs 1866 vs 2133 vs 2400: Key Differences

For us to explain the differences between the four DDR3 RAM chips mentioned, we need to recognize what you’re able to buy. With RAM, there are usually two considerations: memory and speed. The number after these DDR3 chips shows different speeds, expressed in megahertz (MHz) or mega transfers. Upgrading speed and getting more memory can enhance your PC’s performance.

If you’re already working with 8GB RAM, you’re probably handling most tasks and games easily. In that case, you’ll want to work out the differences between DDR3 1600 up to DDR3 2400. In basic terms, DDR3 1600 is the slowest, and DDR3 2400 is the fastest. 

It seems pretty simple to set them apart, but there are other factors at play. If you’re upgrading an existing PC, it’s unlikely that you’ll see the full benefits of DDR3 2400 as it depends on the rest of your hardware.


Working with your existing PC, you might enjoy a subtle improvement with DDR3 1600 or DDR3 1866. If you already have some RAM and are adding another stick, it’s crucial to pay attention to the different specifications mentioned in the table. 

All four have different timings, and one has a different voltage. You can cause problems using two types of RAM running off different timings and voltage, so find one that matches what you have.

Otherwise, compatibility between these four DDR3 chips isn’t an issue. We advise against mixing and matching, but whether you get DDR3 1866 or 2133, it should fit your motherboard. 

DDR chips aren’t backward or forward compatible. However, all DDR3 types should work in the same slots. Keep in mind, you might need to go into your BIOS to set the correct speed. 

As you’ll notice from our specifications table, each of the four DDR3 RAM differs in latency. However, there are crossover points where you could find slower speeds with the same latency as higher ones. We’ve given the range, for example, you could buy a DDR3 1600 10-10-10 or a DDR3 1866 10-10-10. You might see this expressed as CL10 when purchasing. Once you’ve decided between speed, remember lower latency is better.


It’s useful to keep in mind that speed at the lower end, so DDR3 1600 and 1866 will give you a subtle but noticeable boost in your processing power. If you use software for rending or editing, then it’s likely that the speed increase from either of these two will give you the boost you need.

At the other end of the spectrum, DDR3 2133 and 2400 are more likely to impact your gaming. There are two metrics you might be interested in, frames per second (FPS), which you can look at as an average or minimum. The difference between DDR3 2133 and DDR3 2400 will mean a different rate of FPS in a particular game, which could make it appear smoother and have fewer lags.

The speed difference between each DDR3 could be more apparent when you are completing complex tasks or gaming. If you’re using a program with 3D rendering or other advanced features, the extra bandwidth and clock speed will make a difference.

Why Does Speed Matter? 

The faster your RAM can retrieve this information, the more likely it is that your tasks or games will run smoothly. Your CPU handles a lot of the hard work, so the idea is not to have RAM that will slow it down. You must pay attention to speed and memory to get an excellent performance.

When we talk about RAM speed, we’re referring to clock speed, which is measured in megahertz. Clock speed is one part of the speed equation, the other is latency. The clock speed refers to how many times your RAM can access its memory per second. 

It’s sometimes known as clock cycles. 

DDR3 1600: speed 800MHz or 1600MT/s

DDR3 1866: speed 933⅓ MHz or 1866⅔MT/s

DDR3 2133: speed 1066⅔MHz or 2133⅓MT/s 

DDR3 2400: speed 1200MHz or 2400MT/s

All DDR3 chips are named after the speed they give you. The first number, in megahertz, is the clock speed. As these are all double data rate types of RAM, you get two times the amount of data, which gives you the second number 1600MT/s. This rate is the number of mega transfers per second.

DDR3 1600 is the slowest of the selection, which means it won’t deliver as many frames per second as the higher-spec options. This slower speed might not be noticeable if you aren’t asking your RAM to process large chunks of data. As you move up through DDR3 1866, 2133, and 2400, the FPS will improve, making 3D renders and games run more smoothly.

Why Does Latency Matter?

The other part of the speed equation is latency, also written as CAS latency or CL. It refers to the delay between your RAM receiving a command and then being able to issue the data. Low latency numbers are positive, but as we’ve already mentioned, they’re only one part of the story.

If your RAM has higher latency numbers, that doesn’t mean it’s slower. RAM with high megahertz combined with high latency numbers can still be faster than RAM with lower latency. 

You can use a calculation to add the two elements of speed to understand RAM timing in nanoseconds, which might help you compare different speeds and latency numbers. 

(CL/Speed) x 2000 = latency in nanoseconds.

DDR3 1600: latency 8-8-8 to 11-11-11

DDR3 1866: latency 10-10-10 to 13-13-13

DDR3 2133: latency 11-11-11 to 14-14-14

DDR3 2400: latency 11-11-11 to 16-16-16

These figures give you an indication of the range that you can find when buying RAM at these speeds. Once you use the calculation for different speeds and latencies, you’ll see that the differences between chips are very subtle. For example, DDR3 1866 with CL12 gives a total latency of 12.8 nanoseconds compared to DDR3 2133 with CL14 is 13.1.

Finding DDR3 2400 with CL11 is going to bring you 9.1 nanosecond latency. That’s the shortest delay, so if you’re looking to get the most out of your RAM regardless of cost or extra power, then you can focus on latency. The bottom line is you need to work out how latency balances with speed. 

Why Does Performance Matter?

When we talk about performance, we are mostly talking about the power the RAM requires. However, that ties into the bigger picture of performance, as RAM doesn’t work on its own. It needs to work with other components that make up your computers, such as your motherboard and CPU

We measure the power or performance in voltage. It might be possible to find low voltage versions of the chips we have listed. However, they come in at the rates we have shown. If you find DDR3 1600 at 1.35V, that could be beneficial, but check the compatibility with your motherboard. If it doesn’t support that voltage, then it will run it at 1.5V anyway.

Voltage is a small piece of the puzzle that is computer specs. Lower is better. However, there is only one advantage to going lower and one disadvantage of going higher.

DDR3 1600: power 1.5V

DDR3 1866: power 1.5V

DDR3 2133: power 1.5V

DDR3 2400: power 1.65V

Getting DDR3 1600, 1866, and 2133 at 1.5V or lower might mean there is some room to overclock your RAM. That means you can improve the speed yourself. If you don’t want to mess around with the specifications, then the major advantage of going for lower power is that your chip will consume less electricity than the DDR3 2400 at 1.65V. 

More electricity means more heat, and this can increase the wear and tear on the chip and other components, like the motherboard.

Why Does Theoretical Bandwidth Matter?

Theoretical bandwidth refers to the peak data rate of a particular RAM module. It’s measured in megabytes per second, or you might see gigabytes per second. You might also see a reference to this number as a module written as PC3-12800 or PC3-14900, which shows that it’s a PC module from the third generation, and the number represents the MB/s.

The figure relates to the width of the channel, which is a 64bit wide memory channel or 8 bytes. Since it’s double the data rate, the result is 12,800 if the speed is (800MHz x 2) x 8 bytes. This number is theoretical; you can test your RAM capacity using benchmarks when accessing data. It’s usually less, as your RAM doesn’t maintain that speed all the time. 

This information could be useful if you’ve got an idea of how hard your RAM will work and you want to quantify that. For example, if you create your own programs that rely on retrieving large amounts of data, then you can use the bandwidth to see if your RAM will be up to the task.

DDR3 1600: 12,800MB/s

DDR3 1866: 14,900MB/s

DDR3 2133: 17,000MB/s

DDR3 2400: 19,200MB/s

As theoretical capacity is affected by speed, it’s no surprise to see that DDR3 2400 has the highest spec. If you’re not completing demanding tasks that need to retrieve large amounts of data at once, then DDR3 1600 or DDR3 1866 will suit you. If you know that there could be times when you’ll make your RAM work harder for 3D renders or high-end games, then DDR3 2133 or DDR3 2400 could help you handle that and do it faster. 

Winners and Losers of the RAM Showdown: DDR3 1600 vs 1866 vs 2133 vs 2400

Speed: 1600 | 1866 | 2400 | 2133

With speed, DDR3 2400 wins. It has more mega transfers per second than the other chips. Even if it has some other downsides like power and cost, it’s still the fastest. 

Value: 1600 | 1866 | 2400 | 2133

That brings us to value, which DDR3 1866 wins by a long shot, but you could get good value out of DDR3 1600 as well if bought at the right latency. However, DDR3 1866 will give you a noticeable difference in smooth and fast processing tasks and casual gaming.

MHz vs Latency: 1600 | 1866 | 2400 | 2133

When you combine the best latency with the best speed, DDR3 2400 comes out on top. You can end up with 9.1 nanoseconds of latency, which is the best out of all these RAM modules.

Performance: 1600 | 1866 | 2400 | 2133

 However, once you bring power into the mix, DDR3 2133 wins, as it delivers good speeds at 1.5V.

People Also Ask

If you’re still wondering which RAM to buy, these answers to common questions can help.

Can I Mix 1600 and 1866 RAM?

Yes. You can mix modules of different speeds. However, you will run both modules at the slowest speed instead of being able to take advantage of something faster.

Does DDR3 Memory Speed Make a Difference?

Yes. Memory speed can improve how quickly your computer retrieves data. That data could be used for editing an image or creating the graphics in a game. If you can retrieve more data in less time, you might find that the process is smoother and faster.

Does RAM Increase FPS?

Yes. RAM can affect your frames per second. Some games require a certain amount of memory to run, and if you start without enough, you could experience issues in your game. In that situation, more RAM in terms of memory and speed will increase the amount of data transferred in a timeframe and improve the FPS.


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