The Voltage Regulatory Module (VRM) section in the motherboardsteps downthe raw12 Vpower supply to1.2to1.45 Vrequired by the processor, RAM, and other components.

While this isn’t the first thing that pops up in our mind when choosing a motherboard, it’s still essential, especially for overclockers.

If you’re seeking higher clock speeds, know that it requiresclean and stable voltage, which is only possible withhigh-quality VRMs.

If your motherboard consists of a low number or poor-quality VRMs, it can significantly impactits lifespan.

It may mess up the power delivery and even lead tofrequent crashing,blue screen errors, andpermanent damage to your PCcomponents.

Buckle up as I’m going to discuss everything you should know about motherboard VRMs in this in-depth guide.

Motherboard VRM Constituents

Let me clear this confusion right away – the12 V supplied by the PSUdoesn’t directly reach the processor.

It passes throughdiodes and resistorsbefore landing on the VRM, where the current is stabilized andvoltage is stepped downas per the CPU’s requirement.

The Voltage Regulatory Module is composed of severalMOSFETs,chokes, andcapacitors. Each of them has a specific function and is essential for proper/clean power delivery.

These components are well scattered around theprocessor socket. Without them,your CPUwould fry out. That said, here are some basic things you should know.

MOSFETs

As the name suggests, themetal-oxide-semiconductor field-effect transistorsare responsible for opening and closing the electronic gates. This means the inductors/chokes are charged onlywhen the switch is closed.

These transistors sit underneath the VRM heatsink. So, it’s pretty easy to guess that these components are the ones thatproduce the most heat. That’s simply because a MOSFET has to open and close thousands of times per second.

While they are designed to withstand temperatures up to 150 degrees,they will eventually dieif overheated. That’s the reason most boards come with a dedicated sensor so you cancheck the MOSFET temperaturefrom time to time.

In the past, motherboards used to come with a set of MOSFET chips –high and low side switches. But in modern models, you’ll only find a single transistor that contains the functionality of both.

Chokes

These are magnetic inductors that sit next to the MOSFETs,outside the heatsink. Chokes are much easier to spot on older systems as you may see thelarge coilsquite clearly.

On the other hand, themotherboard that we owntoday has asquare-shaped blocky design, and the coils are safeguarded there.

When the circuit is closed, the inductors start toget charged. At this moment, the electric energy is converted to themagnetic fieldand your CPU gets sufficient power. More on this later.

Capacitors

As with any other electronic device, even motherboards are equipped with a large amount of capacitors. Thesecylindrical-shaped bodieshave an operating limit and life expectancy.

For example, in some motherboards, capacitors are rated to operate at the maximum temperature of105 °C.

So, if themotherboard temperaturegoes beyond the limit (especially due tovoltage spikes), they may bulge or even pop.

Usually, motherboards designed for better overclocking contain high-qualitysolid-state capacitors.

Avoid the cheap ones that haveconducting liquidsand have a higher chance of rupturing, thusrendering the motherboard useless.

Capacitors are meant to correct thevoltage ripple and spikes. They act as batteries that store the additional electricity (usually, in a small amount), and convert it into stable and consistent voltage.

PWM Controller

This is themaster control chipof the VRM as it instructs all the core components (MOSFETs, chokes, and capacitors) for the proper functioningthrough pulse signals.

In the past, the PWM controller on a majority of motherboards used analog signals. The newer boards now utilizedigital PWMs, but that doesn’t mean the analog ones are completely superseded.

This component is also responsible formonitoring and regulating voltage, taking theVREF (Voltage Reference)availablein the BIOS settings.

There might not always be aPWMindication on the dedicated chip. For instance, myTRX40 AORUS MASTERlabels it asDAU1.

Likewise, some boards come with aDr MOSchip, which works using external pulse-width modulation.

Working of the Voltage Regulatory Module

Now that you have the general concept of each VRM component, let’s see how thebuck converterworks to step down voltage and distribute power efficiently. I will use bullet points to make this easier to understand:

What Exactly Are Power Phases?

Don’t get so confused by the term ‘power phase’. You have already mastered this if you have properly understood the previous explanation.

Just know that thecombination of a MOSFET, choke, and capacitorforms one phase. Similarly, another set of the specified VRM components forms the second phase, and so on.

For example, if a CPU requires80 Acurrent to operate, all of it will pass through one circuit in single-phase VRMs. But if your motherboard has four phases, each circuit will handle20 Acurrent.

The more the number of phases,the better the power is split. The process even leads to a high number of‘switching losses’, which can be controlled through multiple phases.

That also calls for amulti-phase PWMfor better voltage regulation. Meaning, one PWM controller is dedicated to one VRM phase.

Forbetter overclockingsupport, high-end motherboards are all equipped with more power phases. Also, they come with better cooling through top-quality heatsinks.

If you want to identify the number of power phases on your system board, this can be simply done through physical inspection.Counting the number of chokesshould be enough.

Inspecting the number of capacitors and MOSFETs isn’t the right approach though. That’s because some boards adopt thephase-extend topology(whereVRM doublersare used).

We will have a detailed guide on Twin and Phase-Extend VRMs soon. For now, just take a peek at the illustration below:

Here, the inclusion of a phase doubler splits the frequency coming from the PWM controller. But the one without a doubler will send the same signal (without any delay) to both phases.

Understanding VRM Specs When Choosing a Motherboard

Wheninspecting the motherboard specifications, most people overlook the importance of VRM. In fact, some boards (including myMSI B550M MORTAR) don’t include anything about such.

Gigabyte boards often designate the VRM specs inX+Yformat. For example, myTRX40 AORUS MASTERhas16+3 power phases. Here, 16 is for the CPU and 3 for RAM.

Also, it’s worth noting the‘70 Apower stage’, which simply means the motherboard can supply 70 A current to the processor. And as explained earlier, with 16 power phases for the CPU, each phase handles4.375 A.

Some older boards might show this in theX+Y+Zformat. X is usually for the processor, while Y and Z are for other components, one of which is for memory.

Most ASRockcomputers that we ownonly indicate the total number of power phases. For instance,X570 AQUAhas a total of 14 whileX370 Taichihas 16.

However, it doesn’t specify the exact number for CPU and RAM. So, I suggest counting the number of chokes to find this out yourself.

What I’ve noticed on modern ASUS boards is most come withDIGI+ VRM. Well, it simply refers to the digital voltage regulator, which is far better in terms of power stability and overclocking compared to analog.

You see, every motherboard is different, and the number of power phases along with topology is unique. But now that you’re aware of most stuff related to VRM, this shouldn’t be a factor to worry about.

Kindly note that your motherboard VRM isn’t the only thing that deals with power delivery. Whenbuilding a PC, you should alsochoose a PSUwith top-notch quality and withgood efficiency.