does micro variant of all the ATX AM5 mobos has same vrm quality?

[EzioWar]

does micro variant of all the ATX AM5 mobos has same vrm quality? as an example- is vrm quality of ASRock B650M Pro RS and ASRock B650 Pro RS same?

[RONOTHAN##]

Depends on the board, sometimes it's the same, sometimes it's slightly worse, and other times it's not even close. The B650M Pro RS is a bit worse than the ATX version, but not enough to care in most instances. The MSI B650M P Pro is way worse than the ATX version of that board. The B650M Aorus Elite AX is barely worse than the ATX version. 

[EzioWar]

10 hours ago, RONOTHAN## said:

Depends on the board, sometimes it's the same, sometimes it's slightly worse, and other times it's not even close. The B650M Pro RS is a bit worse than the ATX version, but not enough to care in most instances. The MSI B650M P Pro is way worse than the ATX version of that board. The B650M Aorus Elite AX is barely worse than the ATX version. 

Tyvm,

 AMD B650 Motherboard Roundup: VRM Thermal Testing | TechSpot

AMD B650 Motherboard Roundup: 35 Motherboards Tested | TechSpot

i'm following those 2 links for choosing good vrm mobo, but those links dont have any info about micro atx variants of those boards. how can i determine if those micro atx variants have good vrm or not?

[RONOTHAN##]

36 minutes ago, EzioWar said:

how can i determine if those micro atx variants have good vrm or not?

There's ways to figure out how a board compares to others visually and from the product page. The two main ways are to just visually compare the heat sinks and look at the phase count/power stage rating (note that this only really works when comparing boards from the same vendor)

 

For visually, look at photos of a pair of boards like the B650M PG Lightning and the B650 PG Lightning. The ATX version has a massive heatsink on both the top and left side VRMs, while if you look at the mATX board the heatsink is half the size of just one, so the mATX version is going to have much less cooling and therefore run hotter. Granted, a heatsink can be massive but not cool correctly, but with the same manufacturer, the heatsinks should be similarly functional. 

 

For the power stage count/rating, this is somewhat reliant on the motherboard vendor having that information listed on the product page. For the aforementioned lightning boards, the mATX version has a 6+2+1 phase layout, while the ATX version has a 14+2+1 phase layout. If the motherboard vendor doesn't list the phase count, you can usually figure it out by looking at the VRM and counting the grey rectangles and assuming 2-3 of them are for the SOC and VDD_MISC rails with the others being reserved for VCore. On average, more phases is more better for VRM temps, and since the first number is the VCore phase count (the main part that gets hot), you want that to be as large as possible for the best possible VRM, though there is diminishing returns past ~12-14 phases, and a better heatsink on a worse VRM can result in that VRM being better overall. 

 

Another think is that if two boards have the same phase count, same power stage rating, and a similar looking heatsink, odds are the VRM is just copy-pasted from one board to another, so you can look at reviews of the other board and get relatively accurate numbers for the performance of the VRM. 

 

Neither of those are replacements for finding full reviews of a motherboard to figure out whether something is actually good or not as there are cases of a heatsink looking adequate with a good number and quality of power stage but the board having a worthless VRM (B550M GTQ, for instance), this is just a decent way to get a rough estimate on whether it's worth trying to find a review. 

[EzioWar]

33 minutes ago, RONOTHAN## said:

There's ways to figure out how a board compares to others visually and from the product page. The two main ways are to just visually compare the heat sinks and look at the phase count/power stage rating (note that this only really works when comparing boards from the same vendor)

 

For visually, look at photos of a pair of boards like the B650M PG Lightning and the B650 PG Lightning. The ATX version has a massive heatsink on both the top and left side VRMs, while if you look at the mATX board the heatsink is half the size of just one, so the mATX version is going to have much less cooling and therefore run hotter. Granted, a heatsink can be massive but not cool correctly, but with the same manufacturer, the heatsinks should be similarly functional. 

 

For the power stage count/rating, this is somewhat reliant on the motherboard vendor having that information listed on the product page. For the aforementioned lightning boards, the mATX version has a 6+2+1 phase layout, while the ATX version has a 14+2+1 phase layout. If the motherboard vendor doesn't list the phase count, you can usually figure it out by looking at the VRM and counting the grey rectangles and assuming 2-3 of them are for the SOC and VDD_MISC rails with the others being reserved for VCore. On average, more phases is more better for VRM temps, and since the first number is the VCore phase count (the main part that gets hot), you want that to be as large as possible for the best possible VRM, though there is diminishing returns past ~12-14 phases, and a better heatsink on a worse VRM can result in that VRM being better overall. 

 

Another think is that if two boards have the same phase count, same power stage rating, and a similar looking heatsink, odds are the VRM is just copy-pasted from one board to another, so you can look at reviews of the other board and get relatively accurate numbers for the performance of the VRM. 

 

Neither of those are replacements for finding full reviews of a motherboard to figure out whether something is actually good or not as there are cases of a heatsink looking adequate with a good number and quality of power stage but the board having a worthless VRM (B550M GTQ, for instance), this is just a decent way to get a rough estimate on whether it's worth trying to find a review. 

Tyvm, is there a way to know if a board has discrete MOSFET or not? cause even official website says Gigabyte B650M K has 8+2+1 Phases vrm though cause of having discrete mosfets the vrm is not good ( source techspot).

[RONOTHAN##]

1 minute ago, EzioWar said:

is there a way to know if a board has discrete MOSFET or not?

Photos of the board are the easiest way. If you see more than 2-4 black rectangles per inductor, it's a discrete MOSFET board. 

 

Granted, discrete MOSFETs aren't necessarily bad, you can design a good board that uses discrete MOSFETs, it's just harder than designing a good VRM with power stages. 

[EzioWar]

4 minutes ago, RONOTHAN## said:

Photos of the board are the easiest way. If you see more than 2-4 black rectangles per inductor, it's a discrete MOSFET board. 

 

Granted, discrete MOSFETs aren't necessarily bad, you can design a good board that uses discrete MOSFETs, it's just harder than designing a good VRM with power stages. 

 

Tyvm, this is Gigabyte B650M K. can u please point out which are inductor and black rectangle u were talking about?

[RONOTHAN##]

7 minutes ago, EzioWar said:

 

Tyvm, this is Gigabyte B650M K. can u please point out which are inductor and black rectangle u were talking about?

Red are the inductors, blue is the MOSFETs.

[EzioWar]

8 minutes ago, RONOTHAN## said:

Red are the inductors, blue is the MOSFETs.

tyvm, u are the savior, cant thank you enough.