Motherboard VRM heatsink: Budget option with Replacement

The success of a budget motherboard on the market is determined by what consumer qualities and functionality it can offer for the same price or even less than its competitors. At the same time, in order to reduce the price, it is not necessary to save only on the quality of components:

you can simply order a giant volume of a certain product from the supplier, increasing the payback of its equipment, and request a reduced price for yourself. This is exactly what happened with the comb-shaped heatsink on Gigabyte motherboards, which has celebrated a decade in the ranks.

The latest Gigabyte b550m s2h uses the same VRM heatsink as the Gigabyte GA-Z77MX-D3H from 2012…

What is the motherboard vRM heatsink?

A VRM heatsink motherboard is a type of motherboard that features a built-in heatsink for the voltage regulator module (VRM). This type of motherboard is designed to provide better cooling for the VRM, which can help to improve system stability and performance. Most VRM heatsink motherboards are also equipped with additional features, such as enhanced power delivery, overclocking support, and more. If you’re looking for a motherboard that offers superior cooling for the VRM, then a VRM heatsink motherboard is definitely worth considering.

Budget motherboard: with or without a heatsink?

The mere presence of a heatsink on the VRM on a budget motherboard already puts it in an advantageous position over equivalent competitors, especially considering the impossibility of adding such an element on most inexpensive motherboards later. Often, in disputes, it is recommended to take a certain model with a more powerful power system for two to three thousand rubles more, but given the low initial price, this will lead to a one and a half times increase in the cost of the motherboard, while the presence of interesting alternatives in the new price range will make the choice not so obvious.

motherboard vrm heatsink
motherboard vrm heatsink

In the price range where Asus TUF b450m PRO Gaming performs, its rival will be the full-sized MSI X470 Gaming Plus MAX with improved MOSFET

At the same time, if we compare the budget board Asus b450m-k in terms of VRM power and one and a half times more expensive Asus TUF b450m-plus gaming, it turns out that all the differences are only in the use of a massive heatsink in the latter. Yes, and Asus TUF b450m PRO Gaming, which is considered quite successful, uses the same mosfets, but with doubling instead of the previous one and a half phases and with a more rational distribution of them under the radiators. Considering that, according to the specification, the maximum allowable current in the most loaded MOSFETs 4C06 of the lower arm of the VRM power phases drops from a nominal 69A for 25 degrees to 52 for 80, then the use of decent radiators is absolutely justified here.

About VRM temperatures with a pre-installed heatsink

Let’s get back to our “budgets”, which in some cases have to take the rap for their older relatives, especially after processors with 6-8 cores have become affordable.

Then, not the most ventilated case and the location in the niche of the computer desk played their part, warming up the VRM in a stress test in 10 minutes to 85 degrees.

After that, I perforated the front panel of the system unit and replaced the blank computer niche with a shelf.

The situation with temperatures has improved, 79 degrees in 20 minutes:

temperatures after perforating the front panel
temperatures after perforating the front panel

Replacing motherboard vRM heatsink and its effect on temperatures

However, I was haunted by the fact that on the same Asus TUF b450m PRO Gaming on similar OnSemi mosfets, the VRM temperatures are much lower. Therefore, I decided to experimentally check how the VRM temperatures of my budget motherboard will change with a more powerful heatsink on mosfets of four one and a half phases. By analogy with the Asus TUF Gaming b450m-PRO S, it was decided to use all the available space between the socket and the rear interface panel for the radiator, adjusted for the shape of the profiles of commercially available aluminum rolled products. After weighing the price offers and the height available under the Thermalright Macho 120 Rev.A CPU cooler, I chose the domestic profile ABM-053 from the AD31 alloy:

Profile section AVM-053

In addition, a 5.5mm thick ribbed aluminum plate was ordered from a well-known Chinese trading platform for the manufacture of a backplate radiator: this is a more effective analogue of the backside bar on the back of the Asus TUF b450m PRO Gaming PCB. 

Comparative dimensions of used aluminum ingots

Naturally, it was not without the purchase of a thermal pad, in my case 1mm thick:

I had to remove one edge from the workpiece so that the heatsink would fit in between the 8-pin CPU power connector and the 4-pin fan connector, and also remove some metal in the area of ​​​​the audio output rack. In addition, in order to preserve the useful cooling area as much as possible, it was decided to do with round recesses at the base of the radiator for putting them on capacitors instead of removing the metal entirely.

 Regular VRM radiator and blank from AVM-053 with the necessary recesses

The structural features of this section of the motherboard can be seen in the photo of Gigabyte b450m H, devoid of a VRM heatsink:

This is what will remain in the memory of the Gigabyte b450m S2H with a standard VRM heatsink:

After installing a new radiator, the board began to look like this:

There is a sufficient distance between the VRM heatsink and the bottom aluminum plate of the CPU cooler:

It is worth pointing out that at first I fixed the radiator without a backplate and with springs on screws, which failed to ensure uniform pressure of the radiator to all mosfets and a slight bending of the textolite occurred. As a result, the first temperature measurement in the stress test did not reveal any positive changes, and under the heatsink a high-quality imprint on the thermal pad was left only by a pair of mosfets closest to the screw.

I then sawed out the backplate heatsink, removing the metal at the top to ensure there was no contact with the case when the motherboard was placed back on the brass standoffs:

This time I refused to use springs for mounting the radiator and by tightening the M3 screws I tried to ensure the maximum uniform pressure of the blank to all mosfets. The fact that everything turned out well, I realized literally in the first minutes of running the stress test, when the VRM temperatures began to rise unusually slowly. As a result, 59 degrees in 10 minutes:

Temperatures in stress test after VRM heatsink replacement

Even taking into account the correction for the difference in ambient temperature of a couple of degrees relative to the previous result, the resulting gain of ~ 20 degrees for VRM speaks for itself. A nice bonus from the reduction in the heat given off to the textolite was the reduction in SOC VRM ( Aux ) heating: for the Gigabyte b450m S2H with a compact power converter layout, the gain was 6 degrees.

Organization of SOC VRM cooling and its efficiency

After the work done on improving the cooling of the Vcore VRM mosfets, it was only a matter of time and ingenuity to equip the board with a SOC VRM heatsink. Due to the lack of special holes in the textolite for mounting the cooler, it was decided to use the top 2 of those designed to fix the motherboard with screws to the case through brass racks. During the manufacture of the part, due to the relatively small load on the power phases of the SOC, a piece of the aluminum profile AVM-077 from the alloy AD-31M, which remained from previous work, was chosen. 

aluminum blank of soc vrm heatsink for gigabyte b450m s2h before installation
aluminum blank of soc vrm heatsink for gigabyte b450m s2h before installation

Of the 6 SOC power supply mosfets, one was already under the updated radiator, to cool the second of the complementary pair with it, it was necessary to make a special protrusion by removing excess metal from the edge. Next, using a rough square file and a flat file, it was necessary to make recesses for the 4 + 4 pin CPU power connectors and the 4 pin CPU fan, as well as the RAM strip. To simplify the manipulations with the above connectors and facilitate the work, the fins from the base of the radiator in these places were completely removed. 

Further, for the correct orientation relative to the edge of the board, the metal in the area of ​​​​the chokes was removed in place and the holes for the screws were adjusted. Due to the chosen method of attaching the heatsink, its installation with a long screwdriver cost even without removing the processor cooler.

The mechanical strength of the heatsink is ensured by moving part of the structure outside the textolite, which also reduces the consumption of thermal pads and increases the heat transfer surface. To compensate for the height of the mosfets and prevent the textolite from bending, metal washers are put on the screws under the radiator. Subsequently, it was decided to use the latter also from above under the screw heads.

You can evaluate the impact of installing a second radiator on SOC VRM temperatures in the diagram below:

temperature graphs with two radiators on vrm circuits
temperature graphs with two radiators on vrm circuits

As can be seen from the graph, during a stress test at about 48 degrees, the SOC VRM ( Aux ) and CORE VRM lines intersect and then the SOC power phases already heat up less, reaching only 52 degrees.


Based on the above material, we can conclude that for the 4C06N/4C10N MOSFETs popular with Gigabyte, due to the use of better cooling, there is a good potential for lowering temperatures and this can be successfully used.

However, the manufacturer himself, even on the charged version of the b450m S2H represented by the B450M Gaming, did not bother much about this, and you will not find a SOC motherboard VRM heatsink among motherboards on the b450 mATX format from Gigabyte at all.