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What is VRM (Voltage Regulator Module)?
VRM or Voltage Regulator Module theoretically refers to the small circuit on the motherboard of a computer that supplies the right amount of voltage required by the processor and regulates its supply.
Technically, this module indicates a buck connector that keeps the power supply to the components consistent. It also acts as a DC-to-DC power converter.
- A Voltage Regulator Module is usually embedded in the motherboard of a computer. However, it can also exist as a separate, small circuit board.
- Whether it is an Intel or an AMD processor, using a VRM allows adjusting the power supply to it without needing the PSU to take on the responsibility of supplying the correct amount of current.
- One of the first motherboards to use such a module was the one that used Socket 7. Today, even the CPUs and GPUs use it to regulate and lower the voltage so that it does not exceed the maximum voltage threshold.
- This particular module plays a significant role in overclocking the processor or graphics cards.
- The sensitive electronics inside the module prevent shorting due to excessive voltage. It is more than a simple piece of wire and at its heart is a buck converter that steps down the voltage precisely to apt levels.
Understanding VRM (Voltage Regulator Module)
The VRM or Voltage Regulator Module of the motherboard is a vital yet underappreciated electronic component.
Its job is to make sure that the Central Processing Unit or the Graphics Processing Unit gets a steady supply of power according to their respective requirements.
The VRM in the CPU typically ensures that the computer is maintaining its voltage requirements.
The power from the supply unit first goes to the VRM.
It is regulated there so that it is below the maximum voltage level of the CPU, which is usually 1.5 volts, and is then sent out.
The CPUs that have their own VRM do not need to use that of the motherboard.
However, if the regulator module is of poor quality, it will not only limit the ability of the processor to function under a heavy workload but will also degrade the performance of the computer system overall.
It may even cause the system to shutdown unexpectedly, especially when you try to overclock the CPU.
Modern computers, however, need multi-phase regulator modules rather than the single phase variants.
These modules are able to disperse the power load over a wider physical area. This helps in several ways such as:
- Reduce heat generation
- Lower strain on components and
- Improve electrical performance.
All these together increase the system efficiency and lower the cost per part.
Each of the phases in these specific VRMs supplies only a portion of the power needed by the CPU and takes turns to meet its entire requirements.
However, the total amount of power supply does not change when each phase operates at a time because every burst is staggered from the previous one.
This, in turn, results in a reliable and smooth source that supplies ‘clean’ power to the CPU so that it can run optimally, which is the optimal goal of the VRM.
Typically, these modules are available in “8+3” or “6+2” form, where the first integer prior to the plus sign indicates the number of phases that are meant for providing power to the CPU.
And the number following the plus sign indicates the VRM phases dedicated for supplying power to the other components of the motherboard such as the Random Access Memory or RAM.
If it is in “4 + 1” or “8 + 2” form, it indicates that the 4 or 8 phases of the modules are for the CPU and 1 or 2 are for HyperTransport or RAM.
However, if the first integer is greater than 8, for example “12 + 1” or “18 + 1” or more, it indicates that the device is a doubler.
It will make use of the phases that are available but will not add any more phases to the board.
How Does VRM Work?
The Voltage Regulator Modules typically function by dispensing the power supplied among themselves. The different phases in it take turns for supplying the needed power to the CPU or the GPU but do so in small portions of the total required amount each time.
As said earlier, first, the 12-volt power supplied by the PSU of the computer is converted to an utilizable voltage which typically ranges between 1.1 volt and 1.3 volt for CPUs.
This is typically done by using three basic components of the module. These are:
- The MOSFETs or Metal Oxide Semiconductor Field Effect Transistor
- The inductors which are also called chokes and
- The capacitors.
The entire working process is controlled by the Integrated Circuit or IC which is sometimes referred to as the PWM or Pulse Width Modulation controller.
In simple terms, the working process of the VRM can be broken down as follows:
- The MOSFET receives the high voltage from the Power Supply Unit
- It charges the inductor till the requisite voltage
- Then the voltage from the choke output is sent to the CPU
- The capacitor stores and provides the energy to ensure it is seamless and ripple-free.
All of these components complete the circuit and supply stable and continuous energy to the CPU by repeating the process.
The circuit is specially designed so that the Low side switch closes when the High side switch opens to start the voltage discharge and vice versa.
With continuous charging and discharging, this ensures a controlled amount of voltage output passes from the choke to the CPU.
In order to enhance the working and functionality, most modern motherboards come with multiphase modules that can clean the voltage for more cycles.
This makes it even more stable and is safer for the system. The more the number of phases, the more will be the stability of the system.
How Important is VRM?
The CPU typically does not need the entire amount of power coming out of the power supply unit. If it gets it all unhindered, it may fry the components instantly.
The VRM here plays a very important role in regulating the power supply by supplying the exact amount of power needed by it in parts. It also ensures that the CPU gets the desired amount of power continuously.
Typically, the hardware components of the motherboard such as the CPU, GPU, and RAM are extremely sensitive to power fluctuations.
These can be damaged permanently even at the slightest variation in the voltage.
The voltage regulator ensures that the voltage is stable, ripple free and continuous irrespective of the component involved.
Apart from this, there are also a few other significance of voltage regulators.
It also helps significantly in overclocking the CPU to make it run faster than its designated speed, which, when done, needs a stable supply of power.
The module will ensure that overclocking is done safely without any fluctuations in the voltage or performance.
The module also helps in preventing damages of the components and getting BSOD or Blue Screen of Death errors.
As you may know all components of the motherboard are connected to each other by some kind of circuitry.
Ensuring a steady supply of power to these components, the VRM does not allow the voltage level to cross the limit and cause serious issues to the system hardware or software.
This will prevent damages and shutting down of the system or getting a BSOD error.
Does VRM Need Cooling in GPU?
The Voltage Regulator Module will surely heat up under load due to the MOSFETs working harder since there is a direct connection between overheating and power consumption.
Therefore, it is very important to keep it cool whether it is in the CPU, GPU, and RAM or in the motherboard.
If the regulator module overheats and the additional heat is not dissipated, it will affect the power delivery which will degrade the graphics performance.
That is why the manufacturers typically combine thermal paste and heat sinks with the high-quality regulator modules.
Passive cooling with a radiator will also help in avoiding overheating issues.
Add to that, the entire system should also be kept cool all the time for an optimal performance overall.
Therefore, when you buy a motherboard, make sure that you look at all the specifications of it including the number of chokes and phases and, of course, the cooling aspect.
What is Inside a VRM?
There is an electronic circuit inside the VRM architecture. This circuit connects its other components inside such as the MOSFET, choke and capacitor.
Each of these components performs different functions as explained below.
The MOSFET is basically a switch and an insulated gate that amplifies or switches electronic signals.
The primary job of the MOSFET and the choke is to defend against the current flow and create a magnetic field instead around it.
This results in a gradual increase of the voltage on the choke output side and generates magnetic energy. This process is referred to as charging.
The MOSFET typically follows the instructions given by the PWM controller which not only monitors the pulse width but also ensures that the choke discharges the correct amount of voltage when the required amount is attained at the output.
The chokes usually come with cube shaped inductors made of metal.
The inductors normally convert the signals of alternating current into direct current or lower frequencies. This stabilizes the output voltage of the MOSFET.
Each of these chokes on the motherboard acts as the power phase.
That is why the higher number of chokes results in a more stable voltage which will help in better overclocking.
Normally, the CPU gets the major part of the required amount of energy from the choke.
Therefore, the choke needs time to get the charging voltage for the subsequent rounds.
The capacitor in the circuit compensates for this and trims down the ripple.
It stores some energy from the previous rounds in it in order to supply the necessary amount of energy in the following round for charging the choke.
Therefore, the capacitors ideally perform dual functions such as:
- It accumulates electric current and
- It stores energy and prevents voltage surges by reducing ripples in the electronic circuit.
In the modern motherboard generations, the electrolytic capacitors are however supplanted by the solid-state polymer capacitors due to their longer life and higher efficiency.
What Temperature is Too High for VRM?
Typically, any standard VRM will work just fine within a temperature threshold of up to 90oC. However, the high-performing variants may work well even at 120 degrees, and sometimes even more, though it will reduce their lifespan.
Though the part may be rated at 125 degrees, the normal operating range should be within 70 to 90 degrees Centigrade, maximum.
Anything above 100 is risky as that will cause damage to the CPU and the system.
If the VRM runs at 100 degrees or more for hours, it will cause the glue to degrade.
The layers of the circuit board will not be together once it happens and may even result in a complete breakdown.
When that happens, the connections between the circuit board and the layers will break or short circuit among several other bad things.
Usually, that is the reason why there is an over-temperature sensor. It detects temperatures nearing 100 or going over that.
In that case, it will automatically turn the board off throttle so that the VRM temperature is reduced.
Therefore, you should reduce the voltage through BIOS or the Basic Input Output System in such situations.
Typically, you should treat the VRM temperature tolerance just as the CPU’s and never ever allow it to cross 90 and reach 100.
Does VRM Need Heatsink?
Usually, yes, a VRM will need a heatsink so that the operating temperature is always right and is well within the maximum limits, and typically, every module does come with one in it.
Ideally, the large metal pad located at the back of the MOSFET is the heatsink.
However, it will depend on a lot of other factors whether or not you will need an additional heatsink for it. These factors are:
- The thermal conductivity of the PCB
- The discrete parts used in the board
- The other active cooling measures present and
- Whether it is a single or a multistage VRM.
If you need one, then where to install it may be a relevant, natural and an interesting question.
Ideally, you should place it at the backside of the board because it is this region that may reach an undesirable temperature.
You can install it by extending the copper thermal pad of the MOSFET to the rear of the board and placing the other Thermal Interface Material or TIM on it.
You can then connect the heatsink to the thermal pad directly.
Is More VRM Phases Better?
Yes, it is better because the more phases you have in the VRM the more stable will be the output voltage, especially if the other components of the computer system are not exceptionally high-performing.
This means that you can get away with a 4-phase module instead of an 8-phase variant if other components are better.
Ideally, in a voltage regulator, there are two distinct sets of power phases. One of them is used by the CPU cores alone and the other is used by the other components of the CPU.
The one used by the CPU cores is located on the left side of the CPU in a typical motherboard and the other is located above it.
However, this may not be the case with the smaller motherboards.
When there is a higher number of these phases, the amount of time for which each phase works will decrease.
For example, if there are two phases instead of one, the time will be reduced by 50%, if there are three it will be 33% and so on and so forth.
In addition to that, a larger number of phases will also result in the following;
- Each phase will be cooler while operating
- The VRM will put out more power and
- The CPU voltage will be more stable.
However, as said before, simply having a large number of VRM phases may not produce the desired results if the quality of the module is not good in the first place.
Therefore, you should also look at the actual components of the VRM and ensure they are reliable and good so that it can handle more power and run at low temperature at the same time.
Is VRM Important If You Are Not Overclocking?
Yes, VRM is quite important even if you do not overclock the CPU or GPU. This is because it will help the CPU run at its rated boost frequency.
In fact, it is better to go for a multiphase VRM in order to provide more stable power.
There are a number of circuits connected in them for the PWM to provide power to each VRM in turn, which reduces voltage fluctuations even more.
So, the multiphase regulator modules can supply more stable power to the CPU.
Questions & Answers:
Does Undervolting Help VRM?
Yes, undervolting will not stress the VRM and provide relief even when you overclock an average chip.
However, if you do not perform stress tests properly, the system may not be stable at the new voltage causing freezes, corruption in the operating system, a Blue Screen of Death and more.
Is VRM Important for Gaming?
As said earlier, the VRM plays an important role in supplying the necessary power to the components.
It may not have a huge impact on the basic and daily performance of the computer but the VRM in the GPU plays a significant role in enhancing gaming performance and experience by ensuring a clean, steady and continual supply of power to the graphics card, especially when it is overclocked.
Where is the VRM Located?
Usually, the VRM will be installed on the motherboard and located close to the CPU socket. However, it can also reside in the CPU if it is its own or in the GPU or in the choke spread close to the memory sockets.
Does GPU Use VRM?
Yes, some of the modern GPUs or graphics cards come with Voltage Regulator Modules in them to help with overclocking and regulate the voltage sent to them in order to prevent them from exceeding the maximum limit.
It can be very difficult to choose the right and a capable Voltage Regulator Module with just cost and the marketing material as your guide, since both of these can be intentionally misleading.
Thanks to this article, you now have enough knowledge and insights to shop for it more confidently.