What Is VRM (Voltage Regulator Module) and How Does It Work? [MiniTool Wiki]
Introduction to the VRM
What is VRM? The VRM is short for voltage regulator module, which can also be called processor power module (PPM). As a buck converter, it provides the appropriate power supply voltage for the microprocessor and converts +5 V or +12 V to a much lower voltage required by the CPU, allowing processors with different power supply voltages to be installed on the same motherboard.
On personal computer (PC) systems, VRM is usually composed of MOSFET (power MOSFET) devices. Some voltage regulator modules are soldered to the motherboard, while others are installed in an open slot specifically designed to accommodate modular voltage regulators.
Some processors (such as the Intel Haswell CPU) have voltage regulator components in the same package (or bare die) as the CPU, instead of using the VRM as part of the motherboard.
This design brings a certain degree of simplification to complex voltage regulation, which involves numerous CPU power supply voltages and dynamic power-on and power-off of various areas of the CPU.
The voltage regulators integrated on packages or bare chips are often referred to as fully integrated regulators (FIVR) or simply integrated voltage regulators (IVR).
Because CPU designers want to use lower CPU core voltages, most modern CPUs need voltages below 1.5V. Lower voltage helps to reduce CPU power consumption. Power consumption is usually specified through thermal design power (TDP), which is the nominal value for designing CPU cooling systems.
Some voltage regulators offer a fixed power supply voltage to the processor, but most voltage regulators sense the required power supply voltage from the processor and essentially act as a continuously variable adjustable regulator. In particular, according to Intel specifications, the VRM soldered to the motherboard should be sensed.
Due to the higher power and current requirements, modern graphics processing units (GPUs) also utilize the VRM. These VRMs may produce a lot of heat and require a heat sink separate from the GPU.
The VRM is usually sold in the form of “8+3” or “6+2”. The number before the plus sign represents the number of phases dedicated to cleaning power for the CPU. The number after the plus sign represents the VRM phases that supply power to other motherboard components (such as RAM).
When the first number is greater than 8, such as “12+1”, “18+1” or higher, manufacturers usually use a device called a doubler. A doubler allows them to take advantage of existing phases without adding other phases to the board.
Although this is not as effective as the completely separated phases, it is indeed possible to make some electrical improvements at a lower cost. And because it allows manufacturers to increase the number of buyers for themselves at a small cost, they often use it.
What is VRM? After reading this part, you should know that, and the following part will show you how the VRMs works.
How Does the VRM Work?
The first thing that the VRM needs to do is to convert the 12-volt power from your computer’s power supply to a usable voltage. For processors, this is usually between 1.1V and 1.3V. Internal precision electronic equipment is easily short-circuited due to excessive voltage.
When powering the processor, accuracy is also important, and the required voltage must be provided as accurately as possible. This is why the VRM is more complicated than simple wires. But in essence, they are a buck converter, which accurately reduces the voltage to an appropriate level.
The VRM uses three components to complete its work: MOSFET, inductor (also called choke), and capacitor. There is also an integrated circuit (IC) for controlling all functions, sometimes referred to as a PWM controller.
How Does VRM Improve Performance?
VRM aims to provide clean and reliable power. However, even a basic VRM can provide enough performance to maintain a mid-range CPU at a medium speed. When overclocking or pushing component limits, the quality of VRM becomes more critical.
Overclockers should look for VRMs made from reliable components. If their components are cheap, they may not be able to provide enough voltage under load, resulting in unexpected downtime.
What is VRM? This post has given you detailed instructions about it. You can know its definition, the work manner, and how the VRM improves performance.