What is Undervolting?
You’ve probably heard about overclocking, but about undervolting you’ve heard or read little or nothing.
In this quick tutorial we explain what it is, what it’s for, its benefits and how we can do it quickly. Is it really worth it?
The architectures of today’s silicon require less energy to operate, also take better advantage of it, but there are basic rules of physics such as that the more energy consumption more energy transformed into heat.
The less heat, the better an electronic component works (up to certain limits at very low temperatures) so when we reduce the consumption of one of our components will improve the temperature of this one and consequently we will also make it more stable.
Even so, not everything is so simple so we’re going to tell you what Undervolting is, because some users perform this technique and we’ll see the basic steps of how to do it on your CPU or GPU.
What is undervolting?
Undervolting is nothing more than reducing the standard working voltage of electronic chip. This means that if our processor has a working voltage of 1.2v to develop its full potential, we can force it to reduce that consumption to ultimately improve its thermal behavior.
The objective of this technique is to perform this process without losing all the potential of the processor, although sometimes it can be combined with other techniques such as underclock, to further improve the main objective of Undervolting.
As you can see the concept is simple, now we will see exactly what we can get out of it and when it is most useful this type of technique is that it is very easy to execute and can be useful in many occasions.
What’s it for?
Undervolting reduces the consumption of the processor, GPU, or other encapsulated components.
By reducing consumption we will improve energy efficiency, i.e. we will consume less and less energy will be transformed into heat so we will need less cooling to keep our component running.
Less cooling also means less noise and also that we can mount that component in environments where cooling, by size, is a bigger problem.
Undervolting is done a lot in cryptomontage mining with GPU because in sustained stress for a long time every watt of consumption is important, because we will earn more money, but it is also important because we will reduce the thermal stress of the component and therefore it will last longer.
As you can see, Undervolting is fundamental for a miner of crypto coins, but it can also be fundamental for any user.
Every electronic component, or rather every silicon processor, no matter how complex, has some degrees of quality in its production, for example, the wafer edge processors are usually of lesser quality by the lithography process itself.
This means that the manufacturer always gives an interesting range of voltages that supports his silicon to work well whether it is of high quality or not.
With that power margin is the one that the user plays with to perform Undervolting without losing performance or without losing stability and in some cases, especially in GPUs, also improves the ability to overclock.
As you will understand we will also have, as in the case of other techniques, better or worse result depending on the quality of our chip. So there is some randomness in the result as it happens when we overclock, which is a more widespread technique.
How can I undervolt my CPU?
Today’s processors have different voltages that are likely to be used in this technique, but the most effective is still touching the vcore or main voltage of the processor.
Currently these voltages are variable to adjust the processor to the states of rest of the system so we have to make the Undervolting in an intelligent way.
If we force a low voltage we can have stability in rest, but not in load and lose, for example, capacity of turbo frequency of the processor, if we use a high voltage, but reduced in the maximum peak of the processor, we will have less consumption in load, but we will have more consumption in states of rest so what we gain on one side we will be losing on the other.
My advice, therefore, is to use a voltage reduction based on a decrease of the relative vcore. Almost all modern motherboards allow it and it is nothing more than reducing a few tenths, which we consider suitable for our objectives, to the variable vcore of the processor. In this way if in load our processor goes up to 1.2v, we will force it to use 1v, and if in rest it uses 0.6v, then ours will be 0.4v.
Each motherboard manufacturer is different but almost all have these options, we will have more difficulties if our motherboard does not have these features, but then we will always have the option to use the Intel XTU application, if our processor is compatible, or the AMD Ryzen Master for AMD Zen processors.
How do I do it on my graphics card or GPU?
The process is more or less similar since modern graphics use processes similar to those enjoyed by modern CPUs.
That is, both use variable voltage systems that adapt to the consumption needs of the GPU based on the needs of the user. Modern graphics processors are thus able to substantially reduce power consumption when full power is not required.
Depending on the graph the setting of one mode or another, we may only affect its maximum consumption mode so when we modify this variable we are only affecting the most demanding states of the card, or that we can detail, as is the case of many recent AMD graphs, multiple voltage levels according to the states that the card admits.
The adjustments, as in the case of a CPU are light, of tenths or hundredths of a volt, but the results are important.
We can use applications like MSI Afterburner or others directly from the manufacturer, as is the case of AMD Wattman, to control this aspect and others.
It will not be possible to perform Undervolting in all the graphs, it will depend a lot on the options that the manufacturer wants to give us to manipulate these aspects of our hardware.
Another option is to modify the bios of our graphic card and flash the bios of it with the updated parameters. It’s doable and easy to execute, but it will invalidate our card’s warranty so it’s something to consider if it’s worth it.
Real differences in consumption and temperature using Undervolting
We’ve done some pretty interesting real tests of how this technique can affect the power consumption and working temperature of important components such as a CPU and GPU.
In our tests we have used standard frequencies for both components, without overclocking, to get an initial idea of the results. This technique, as it is logical, can be combined with others, as the overclock, or also the underclock, to obtain different results.