What are vrm, chokes and their components?

We are going to review the main components that shape the power system of a motherboard, mainly the processor, since the expansion cards use their own voltage regulators and the memories, usually, require less care, although this also is changing in the last generations of motherboards. The key word that we will see in this article is VRM and we will explain in detail everything you need to know.

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Index of contents

What are VRMs?

Solid capacitors next to the Chokes of a Z370 motherboard. The heatsink covers the VRM system with the MosFETs and its controller.

The VRM is an acronym for " Voltage Regulator Module " or " Voltage regulation module " and is an electronic component that allows regulating, with more or less efficiency, the voltage that is supplied in an electronic circuit and in the case at hand to the processor and memories, and to a lesser extent, other components.

A motherboard is powered by an ATX source that, by standard and specification, supplies one or more power rails with voltages of 12v, 5v, and 3.3v. In the past, processors and other components used these voltages directly for power, but the latest generations have significantly reduced their input voltage to reduce consumption, be more thermally efficient, and therefore require less dissipation.

Currently it is easy to see processors working with voltages below the idle volt and just above 1.2v when they are developing to their full potential. Currently all the boards supply 12v to the processor, with dedicated connectors, and from there it is regulated up to the functional requirements of the CPU.

A good regulation of voltage (tension) is essential to give stability to the operation of the processor consuming adequate energy at all times. It is important for overclocking because less voltage (vdroop) than necessary means unstable operation and more voltage than necessary can produce heat generation unacceptable by the refrigeration system and, therefore, instability or catastrophic failures that, luckily, usually Modern processors are protected (to some extent).

Some modern processors chose to pass the VRM control inside the processor's encapsulation, to have a more efficient model and that the processor itself was in charge of the work, Haswell processors worked in this way, calling themselves iVRM (Integrated VRM), but Later Intel models have neglected this type of design relying on the traditional external VRM model on the motherboard. Skylake and later models have returned to the external model.

The more VRM phases, the better

Many times we talk about the number of phases that feed the processor of our motherboard in such a way that it is always implied that the more supply phases, the more correction phases, the better the quality of the electrical signal that reaches the processor. This is certainly so and the reason is simple and it is usually explained by saying that the power supply to the processor arrives cleaner.

The EVGA EPOWER V is a good example of an external and massive VRM system, with 12 + 2 phases aimed at offering an even cleaner line to high-end graphics cards where high levels of overclocking are sought.

When we convert alternating current (which as you know has a sine waveform (generally because there are other types, with a peak and a valley, a period, etc.), to direct current, which is what our processor uses, there is always part of that remaining wave of the conversion. The more phases of supply the more we will eliminate those wave peaks and the more stable the supply will be, which will have a flatter signal, which reaches the processor.

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We will also limit and reduce voltage losses in the power line that are as or more dangerous in maintaining the stability of the operation of our processor.

Accomplices in any VRM system

A voltage regulation system (VRM) requires several important elements, especially warehouses where energy accumulates before passing the filter that is the voltage regulator itself. This task is carried out by the trainers, which are those small warehouses that the MosFETs use, with the gates that allow the appropriate voltage to pass through at the request of the client, in this case the processor.

A VRM is made up of these elements:

• MosFETs ICC Driver Capacitors Chokes or Shocks

We have discussed that the processor tells the MosFETs system what voltage it wants at all times, since now the voltages can be variable, and for this it requires a controller that tells the MosFET what voltage it has to let pass. This is done by the "Driver IC" or "Driver IC".

Many manufacturers have concentrated IC controllers with the MosFETs themselves in solutions called digital VRM or high-efficiency VRM since concentration allows increasing the number of phases, the efficiency, and logically, the heat given off in these elements, which is Logically, they are quite sensitive to heat, but also, depending on the quality, well prepared to work at high temperatures.

Chokes are other basic electronic components in any VRM system. These types of elements serve precisely to convert alternating current signals into direct current. It consists of a spiral that runs through a magnetized nucleus and although they are conductors of both types of currents, their reactance causes the passage of alternating current to be reduced considerably. The quality of a motherboard for overclocking largely depends on the quality of these.

In this Gigabyte Aorus motherboard with X470 chipset we can count 8 alloyed core shocks that form 8 power phases. The main components of the VRM, the MosFETs and their digital controllers are under the aluminum heatsinks connected by a heatpipe.

For each phase that we see on a plate we can count a choke, in fact, it is the most visible element in this type of set-up, and many times we confuse them with the MosFETs themselves, but these, without a doubt, will be the ones that are hidden Underneath the heatsink that all motherboards typically mount for their processor power systems. The key to stability is in them, and in the quality of all the components around them, including the number of layers of the PCB, so nothing can be left to chance.

VRM types

All the current manufacturers have switched to digital VRM systems, compared to the old analog systems or processor-integrated systems, in the last generations and have also concentrated their controllers on control chips such as the ASUS EPU or on integrated ones adding MosFETs and controller as is the case with Gigabyte. The case is to reduce space, increase efficiency, and add more phases when the board has a clear objective for overclocking.

The graphics cards, especially the high-end ones, also use complex digital VRM power systems. Here we see 8 phases with MosFETS on the right (integrated IC) and capacitors on the left on an Nvidia Geforce GTX 1080Ti.

The solid capacitors, the Japanese trainers, the military class components … all these improvements that we have seen arrive at the motherboards have also been replicated to subsystems such as integrated sound cards where even VRM elements specifically designed for this type are used. of functionality.

All in search of reducing those peaks that remain from the AC power supply, especially those that can reduce the voltage (vdroop) on what the processor requests or on what we have configured our motherboard to supply to the processor.

In any case, it is important to keep them dissipated because they are elements that become very hot and sudden. Any energy conversion has loss in the form of heat and this type of element does it in a really fast way since it has to adapt to the sudden changes in frequency of modern processors.

For this reason, many overclockers, even those who are only looking for easily sustainable mid frequencies, want the processor not to change frequencies, even if the overall consumption is higher. and keep VRMs in stable, controlled temperatures and where voltages are perfectly stabilized.

What does it mean when our board says it has 8 + 2 power phases?

It can be 4 + 1, 8 + 2, 6 + 2, 16 + 1… there are as many combinations as the manufacturer wants or can install on their motherboards. More is usually better but as you have also seen the quality of the components is important.

It was crazy times and Zotac released a motherboard with Z68 chipset for LGA1155 socket with 24 phases + 2 phases for RAM. The ZT-Z68 Crown Edition. It had a digital controller, super solid capacitors, superferritic core chokes, etc. The most of the most.

The first figure is the power supply phases of the processor and the second usually refers to the memory banks of the motherboard, 1 or 2 on the most complex boards, although it can also refer to the power of some buses that have some processors, processors that are no longer on the market since now this type of bus is integrated into the processor itself.

The importance of a good power supply

We have talked about the quality of the components of the board, in which the VRM of a motherboard are composed, how we can know how many our motherboard has, the types that exist and how each element works and even how important its dissipation is.

But as much or more important is that the source that supplies that 12v line to our motherboard, to the VRM system integrated in it, is stable is as much or more important than the assembly that our motherboard may have. A stable 12V voltage, in direct current, with a “ripple” or reduced peaks makes our VRM system less stressful when it comes to stabilizing the voltage that our processor requires. This is why DC-DC mountable source designs (with their own VRMs) are so valued by expert users and why investing in a good power supply is so important.

The more efficiency at the source, the less stress on it, the less heat to dissipate, the less vdroop on the source line itself and the less need for correction on our motherboard. It all adds up to achieve perfect stability that improves the chances of overclocking and / or the useful life of our computer.

Final words and conclusion of our guide on VRM

The result of a good overclocking is in the quality of the power that we can provide to the processor, especially avoiding voltage drops (vdroop), but as much or more in the quality of the dissipation that we can apply to the processor. The more cooling the more voltage we can, and the more voltage more cooling we will need since we will increase the transformation of energy into heat.

We will also have to apply the cooling to the processor's power system, to the VRM system, since they are delicate elements with sudden changes in temperature and more voltage, less efficiency and more energy transformed into heat. It is a difficult balance that we will have to know how to handle but that the plate manufacturers have been making easier, especially at moderate overclocking levels, using more capable VRM systems, of higher quality, with more phases and with preconfigured bios profiles in their labs for processors with multiplier overclocking capabilities.