Home Tech What is VRM and How Does VRM Work: The Definitive Guide

What is VRM and How Does VRM Work: The Definitive Guide

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You might have spent hundreds and thousands of dollars on your Graphic card and CPU respectively, but there is one thing that we overlook most of the time,i.e; Voltage Regulator Module, or VRM.

VRM or the Voltage Regulator Module is also known as the Processor Power Module, and as the name suggests VRM works to manage the voltage and ensure the safety of your most expensive components.

VRM is like a mini power supply that converts high voltage to low voltage. It is an electronic circuit that regulates and steps down the voltage from input to output.

It takes high voltage from the main power supply and converts it to a lower voltage like 1.2V which allows the CPU to “maintain its cool” literally! VRM doesn’t allow your CPU to burn off because of that 12V mammoth power that a typical CPU’s main power will offer.

The importance of VRM

VRM is like that member of a family, who always provides without getting much attention. When your computer starts crashing and it’s the ugly blue screen that flashes up, screams that your VRM is in a desperate need for your attention.

So, if you are looking for a new PC. Try taking VRM’s quality in your mind as a good VRM will ensure that your PC will last longer and will serve for years and years to come.

VRM is a very crucial component in a motherboard. It makes sure that your CPU does not overheat and protect your more delicate and expensive components, such as graphic card, RAM, etc. VRM with a small size can lead to malfunctioning of your Graphic Card.

What is VRM and How Does VRM Work: The Definitive Guide

Taking this into consideration many modern graphic cards comes with more modern OCP, which stands for Over-current protection. In this, the Graphic processor is strangled to reduce the amount of current VRM will deliver.

As the components such as RAM, Graphic Card, etc are very stubborn in nature and are prone to overheating if the voltage exceeds the desired voltage. VRM, on the other hand, does not let this thing happen. It changes the voltage from 12V to 1.2V as 1.2V is the desired voltage we talked about.

What is VRM cooling?

Most of the higher-end PCs are respected more because of their terrific performance. So, because of this heavy workload, your PC becomes vulnerable to heat.

To maintain the performance and the temperature of your PC most of the higher-end motherboards have a heat sink.

This heat sink is an elongated extension located near the CPU socket. Which makes sure that the VRM and its MOSFET remain cool. The temperature usually is around 800C and 1000C, but in gaming PCs, it sometimes spikes up to 1200C.

You might be wondering is the heat sink important, can’t I just skip this? Well, there is no hard and fast rule. The use of heat sink depends on your requirement.

If you are not going to play high graphic games like  PlayerUnknown’s Battlegrounds or Grand Theft Auto V you don’t need a heat sink. Or if you don’t want to run heavy graphic applications such as Adobe Illustrator you don’t need this.

Working of VRM:-

You might be wondering how does the VRM work? The VRM is made of MOSFET, Choke, Capacitor, and PWM controller. All of the three-component play a major role in the working of VRM.

The choke is a coil that acts as a mini battery. Choke is an inductor, as we know that an inductor is an electronic component and is passive in nature. It allows the user to store electrical energy in a magnetic form.

MOSFET or Metal Oxide Semiconductor Field Effective Transistor is as the name suggests a field effective transistor. A transistor is a device that controls the flow of current.

And in this case, MOSFET cuts the power of the choke after a certain required limit. MOSFET is well known for its efficiency which makes it an ideal candidate for high power loads.

A Capacitor is a device that ensures that the resulted current is free of any spikes. To ensure the purest result possible.

A Pulse Width Modulation Controller or PWM Controller is a controller used to control the output voltage. Each and every motherboard consists of a single PWM controller per the required voltage level of the CPU, chipset, etc. By running the controller at a higher frequency one can increase the efficiency deliberately.

what is vrm

As mentioned earlier the VRM converts 12V into 1.2V. But the question is how does it do that, what’s the algorithm that’s happening internally? Let’s find out!

VRM does that with the help of Buck Converter. If we look at the basic circuit diagram of the Buck Converter, you will see that the switch is connected to the choke, which is an inductor(all chokes are inductor but not all inductors are choke) used for filtering purposes. Which then is connected to a load(in this case the load is the CPU).

Inductors resist the current changes. They are called inductors because they induce magnetic fields. When the inductor is producing a magnetic field at the same time there will be a voltage drop across the inductor.

In normal circumstances that voltage drop is converted to heat because of ‘law of energy conversation’ which states that energy can neither be created nor be destroyed, it only changes its form, but in the scenario, that voltage drop is converted magnetic fields.

This saves the load from getting heat strokes and it will receive 1.2 units of Voltage which was the required amount.

But eventually when the inductor is charged afterward voltage will again have spike and it will try to nullify the effect of the inductor. The less the inductance the less time will the inductor take to charge and for a very small amount of time it will hold that voltage.

Which means that the circuit is not yet complete. To complete the circuit, we are going to add a diode parallel to switch 2.

what is vrm

Now,  our circuit is complete. But there is still is some small issue. As of right now even after the addition of the diode, our current is still flowing through the switch and you might be wondering why is that a problem? 🤔

It is a problem as after some time when the inductor starts discharging it will hit the ground and eventually your CPU will stop working. So, it will act as a fuse.

As it will don’t let any harm happen to your CPU by just switching it off. I don’t about you guys but for me, it is a problem. So to fix that we are going to make the current flow through the diode and not the switch.

What it will do is that when the inductor starts discharging and the voltage is dropping from 1.2V. It will again spike it up to 1.2 before it hits the 0V margin.

This is how the Single Phase VRM works. If we add more phases the efficiency will increase and the better your system will perform.

VRM is located near the CPU socket of your motherboard as mentioned above in the article. VRM’s circuit is very prominent and can easily be identified because it is the only circuit that uses the inductor(choke).

MULTE I-PHASVRM:-

Most of the computers nowadays use multiphase VRMs. Because as we increase the number of phases the efficiency of the VRM will increase. As the MOSFETs are connected parallel to each other the switching will not be instant.

Therefore, this time delay will be equal to the on-time of the PWM signal. And because they are cascaded the switching will happen in sequence. So, having multi-phase VRM will allow the heat to spread evenly, which will be more profitable in the long run. However, the initial cost will be more

Another benefit of using Multi-phase VRM is that since it allows multiple switching the output voltage which is a damped transient voltage will have less time to drop off

Using multi-phase VRM also allows the PWM frequency of the MOSFET to be lower as the output voltage will be covered because of multi-stage switching. So, the drop, in this case, will always be less than the drop in the case of Single-phase VRM.

One question that you might have is, Hey! Writer, “Does VRM matter if I am not overclocking?” This question does not have a very straightforward answer.

If you are not overclocking you can run the PC without VRM, but the quality of your PC will determine whether you should use VRM or not.

If you have a very high-end motherboard like Asus ROG Maximum XII Extreme, Gigabyte Z390 Auros Ultra, Asus Rog Maximum XI Hero, etc you must consider adding a VRM to your cart while checking out (Note: most of these motherboards come with in-built VRM). If you are planning to buy lower-end motherboards you can go without VRM.

Everything to Know About VRM | What is VRM And Why it is Important

Final Note:-

VRM is very vital for your high-end computers. As without VRM, your computer’s delicate components such as Graphic cad, processor will be damaged due to overclocking.

While going for VRM try opting for a Multi-phase VRM system as because of it being parallelly cascaded the switching will happen more often and hence, the transient voltage drop-off time will be less.