Overclocking is often thought of in the context of a CPU or GPU, but you can also overclock RAM (random access memory) to achieve faster speeds.
The speed of RAM, measured in MHz, refers to its data transfer rate. The faster the data transfer rate, the better the RAM’s performance. Overclocking RAM involves modifying specific parameters such as timings and voltages to allow the modules to operate at greater speeds than they might out of the box.
Altering clock frequency or voltage may void any product warranties and reduce stability, security, performance, and life of the processor and other components.
How Does RAM Overclocking Work?
A PC’s RAM stores data used by the processor. As with any bottleneck, the longer the CPU waits for the information it needs from the RAM, the less efficient the operation. Higher speed RAM can provide data to the processor faster, potentially improving the performance of your PC.
RAM performance primarily depends on its operating frequency, as well as its latency characteristics, which are often referred to as “timings”.
Higher frequency RAM will execute data transfers faster. In the case of timings, however, lower is actually better. This is because each timing corresponds to a certain latency, or the time between operations. The less time between operations, the better.
Frequency and Timings
In an ideal world, RAM would have high frequencies and low timings. The two have to be considered together to determine the overall performance of RAM.
Compromises usually need to be made in order to raise one or lower the other. Simply put, when a memory module operates at a high frequency, it is more difficult to keep it stable. To counter-balance stability challenges at high speeds, memory timings are often increased. This increases the time (latency) between operations, and helps to keep the transfer stable. Increased latency will reduce the performance and potentially eliminate the gains from a higher frequency, depending on the size of the frequency increase.
Memory module manufacturers know this and carefully select memory chips for each stick, testing, and pairing memory modules that can reach the highest possible performance. This additional qualification and effort often results in a higher price, which is why low-latency, high-speed RAM tends to be more expensive.
Both are important, but in general, higher frequencies often outweigh timings when it comes to performance impact for the average user.
Here’s an example of a RAM label that demonstrates frequency and timing specifications. This is a DDR4 module that operates at 3200 MHz frequency. The string of numbers, in this case 14-14-14-34, refer to the stock timings of the RAM.
Establishing a Baseline
When you overclock any hardware, including RAM, it’s important to establish a baseline level of performance before modifying any settings. This will allow you to clearly see the results of your efforts and compare the difference to the stock performance.
Before attempting any overclock, run a benchmarking utility to establish this baseline. There are several programs that will allow you to do this, like memtest86+ (which requires a boot disk), Aida64, MaxxMEM2, or Performance Test software. After running the benchmark of your choice, make sure you keep track of your results for later comparison.
Next, it’s time to start overclocking. We’re going to go over three different techniques for overclocking RAM, depending on whether you’re a beginner, intermediate, or an advanced overclocker.
Beginner Users: Intel® XMP
If you are new to overclocking RAM, you may find that Intel® Extreme Memory Profile (Intel® XMP) technology is a great way to achieve ultrafast speeds without having to dive too far into the details. Intel® XMP-compatible memory modules have their optimal settings predetermined, and many motherboards can detect the settings and automatically apply them without having to modify frequencies, timings, and voltages manually.
In order to find the Intel® XMP settings, you’ll need to enter your PC’s BIOS.
Often the Intel® XMP setting will offer you the possibility to switch between multiple profiles, which provide different levels of overclocking performance. This can vary depending on the motherboard and memory manufacturer, but usually one will provide a more stable overclock, while another might be more ambitious in terms of its performance targets. Pick whichever makes sense for you, and remember you can change it later.
Select the profile you want to use, save and apply your settings, and then reboot your PC.
Intel® XMP makes overclocking RAM simple by applying the correct settings for your modules as per the recommendations from the memory module manufacturer.
In the screenshot above, you’ll see the settings used for our RAM modules:
- Set the memory frequency to 3200 MHz.
- Set Timings at 14-(14)-14-34.
- Set the memory voltage to 1.35 V.
After applying your changes and rebooting, revisit the software you used to get your initial benchmark score, and run it again. In the examples below, we used Aida64, which offers a free trial.
Stock: we score between 32 and 33 GB/s with a latency of 60 ns (nanoseconds).
With Intel® XMP activated, we score between 46 and 48 GB/s. The latency is now down to just 47 ns.
Intermediate Users: Advanced Memory Profiles
While Intel® XMP is simple to use and optimizes performance per the manufacturer’s specifications, it may not provide the flexibility and level of customization some users might want.
If you are interested in making those changes yourself, some motherboards provide access to tools to tweak your memory settings. (Not all motherboards offer these advanced memory profiles; they are usually found on high-end motherboards designed for overclocking enthusiasts.) This is ideal for users who want more granular control than Intel® XMP offers, but aren’t necessarily interested in the minutiae of manually adjusting individual settings.
To begin this process, access your BIOS.
When in your BIOS, explore the menus until you find the section that allows you to tweak your memory profiles. If you are having trouble locating these options, check your motherboard documentation for more information.
Once you’ve found this section, you should have access to a menu from which you can pick between various combinations of frequencies, timings, and memory voltages. Trial and error is often the best way forward here: test the different options until you find the one that works best for your hardware configuration.
In our case, we tried several options, and finally used the 3400 MHz profile. This is a 200 MHz gain over the 3200 MHz Intel® XMP profile, and 734 MHz higher than the stock 2666 MHz frequency. This profile comes with tighter timings, too, which improves our RAM performance overall.
We now measure between 50 and 53 GB/s at a latency of 45 ns.
A clear limitation of our example is the fact that we are using four 8GB modules. One way to reach higher overclocking performance would be to reduce our installed module count to two, as many motherboards have difficulty maintaining higher speeds as the load across the memory slots is increased.
As with other methods of overclocking RAM, you’ll want to restart your system and run a benchmark after every change you make in order to compare results and to ensure the system is stable.
Advanced Users: Manual Memory Overclocking
Advanced overclockers might be looking for even more detailed control, beyond Intel® XMP and Advanced Memory Profiles. If so, making the changes manually might be the best path forward. Keep in mind that this can be time-consuming. It’s not uncommon for even experienced memory overclockers to spend hours for what is ultimately a small increase in performance. That said, this method allows the most precise control over your overclock, which is ideal for some users.
The fundamental principle behind manually overclocking RAM is fairly straightforward, and is similar to the process for overclocking a CPU. It involves carefully adjusting settings such as memory timings from the BIOS in order to find a combination that results in faster speeds, testing to see if the process was successful, and then trying again until you achieve the ideal balance of maximum stable frequency with the tightest timings.
When adjusting RAM frequencies, voltage, and timings in order to find the right balance for your hardware, you’ll want to keep the following things in mind:
- To stabilize higher frequencies, you’ll want to increase (loosen) the timings. This may require increasing voltage as well.
- In order to increase performance when the current frequency is stable, you should reduce (tighten) the timings.
- If you are going for tighter timings, be sure to proceed methodically. With most motherboards, there are a wide array of timings that can be changed through the BIOS.
- Many BIOS utilities display the default timings. For instance, if your memory uses 15-15-36, you might want to try changing it to 14-14-34 as a first step.
- After experimenting with the memory timings, you might need to modify the memory input voltage. As with CPU overclocking, increasing the input voltage of a component will result in higher energy consumption and greater heat output.
- Memory voltage is a key ingredient to achieving a stable overclock. In a standard memory overclocking use case, consider 1.5V as a maximum, but aim for lower whenever possible. Be conservative with voltage changes, and keep them as low as possible when testing.
- Some motherboards do not support high-memory voltages, and consequently will not boot when you push the voltage too high. Try a lower voltage.
- When overclocking RAM, there is often a ceiling at which point pushing things higher will not yield additional performance gains. Once a certain frequency is achieved, further increases may not yield better performance because the motherboard automatically adjusts timings to keep the system stable. If you’re finding that you aren’t gaining additional performance after continued adjustment, it’s possible that you’ve reached the limits of what’s capable with your hardware.
- It might take a fair amount of experimentation until you find the right combination of frequencies, voltages, and timings for your hardware.
- Make small, incremental changes to any settings, and test for stability between each attempt.
When you have modified the settings into a combination you believe might be successful, reboot back into Windows, and test by using a benchmark utility to verify stability and performance gains. If you want to keep trying for better performance, head back to BIOS and continue the testing process.
Save your settings each time you find a combination that results in a successful boot and overclock, even if you want to keep trying for better performance. It’s possible that many of your attempts will not be successful, and any changes you make will be lost after a failed trial. Making sure you save as frequently as possible will save you time, and keep you from having to start over with every new attempt.
If your system doesn't boot after applying new settings:
- Try slightly increasing the memory voltage, and the IMC voltage, to allow for higher frequencies. Be cautious when pushing voltages higher. Do so in small increments, and heed any warnings provided by your motherboard.
- Decrease the frequency to a lower level, and try again.
- Change your timings. Some combinations of frequency and timings won’t work. The only way to find out is to continue testing until you are successful.
Getting the Most from Your RAM
Overclocking RAM is a relatively simple way to get a little more out of your hardware, and it can have a serious impact on system performance. Following the steps above should help make sure you’re getting the fastest speeds possible from your RAM, and the most out of your build.