VRM: How to identify GOOD and BAD mobo's?

[AntiSpiral]

Hellouu!!

Everytime I upgrade my system I come for online wisdom when I have to choose a good non-expensive mobo. 

My point now would be like: how can I identify and discard a bad mobo from a good one? I know VRM  is the way to go on this matter, but that's not a thing that comes specified on the manufactured site, so even though that I know a bit about it I'd like to know tips to dive deeper into this matter.

 

Thanks in advance!

[Haro]

Well just looking at the boards images, you wont really know much about the vrm, if you want to know more about whatever a board uses, you  can watch a pcb breakdown, made by buildzoid, and those are quite detailed if you want to learn more about vrm and/or find out what a board uses for it's vrm. 

But yea Buildzoid does pcb break downs and you can learn quite a bit about vrm from him.  

Or for a more simplified one, hardware unboxed does reviews about boards and checks their vrm temps. 

[WereCatf]

9 minutes ago, AntiSpiral said:

My point now would be like: how can I identify and discard a bad mobo from a good one? I know VRM  is the way to go on this matter, but that's not a thing that comes specified on the manufactured site, so even though that I know a bit about it I'd like to know tips to dive deeper into this matter

The easiest method would be to simply read/watch reviews that mention such details, like e.g. Hardware Unboxed on Youtube does pay good attention to VRM-performance.

[Mateyyy]

Talking in very general terms - the number of chokes present around the CPU socket is generally a decent enough indication of how good the power delivery is on a board. That should give you an idea of how many MOSFETs (or more commonly just called phases) are present underneath those heatsinks.

 

Now, more phases/MOSFETs doesn't necessarily mean better, or at least not in terms of current handling capability - what really matters is what is actually underneath those heatsinks. You could have however many phases, but if they're just some crappy discrete MOSFETs underneath, that VRM is still going to be outperformed by a setup with half the phases but using good power stages.

 

Finding the actual components used is often quite a bit trickier. Lately, Gigabyte and MSI have been mentioning roughly what they use on the actual board's page, especially on their mid to high-end offerings.

Spoiler

 

They don't mention the exact power stages that are used (NCP302155 in this case), but "DR. MOS 55A" is good enough, imo.

Basically, each power stage is rated for 55A of current handling (in theory), and "Dr. MOS" means that they're "dumb" power stages. They don't feature any sort of thermal or current monitoring, but do have the basic functionality of shutting down when overheating thanks to a simple flag.

Spoiler

 

Again, the exact component choice isn't mentioned (ISL99390s), but they do let us know that they are smart power stages rated for 90A of current handling.

90A is about as high-end as you're going to get with power stages, when it comes to current handling. That's not to say that they are the be all and end all though - realistically speaking, 70A stages should be just as good, since their efficiency curves are, for the most part, very similar.

 

The fact that they're smart power stages means that they have current and temperature sensing built-in. What this means to you is more accurate VRM readings when you open up your hardware monitoring software of choice (ideally HWiNFO64).

Then there's other manufacturers like ASUS which will at most mention "Dr. MOS" regarding the VRM, and that's about it.

 

Also, one thing I mentioned a few times above was heatsinks - they're also very important. More surface area = more better, and less random plastic junk also = more better.

I think MSI's been the best at this lately, where they've been making the rear IO cover out of metal as part of the heatsink.

On the other hand, there's boards like the B550M Aorus Pro which will have plastic rear IO covers acting pretty much like heat insulators - not letting any incidental airflow in, and not letting the heat put out by the MOSFETs out. That's no bueno.

 

I would recommend looking through Buildzoid's PCB breakdowns, where he also talks about boards' power deliveries in detail, among other components:

https://www.youtube.com/playlist?list=PLpS0n7xxSadV6Gkwzv928N1MT68Nd1muu

Reviewers like Hardware Unboxed also do share details about the VRMs on boards they review, along with thermal testing. 

 

(hopefully this is somewhat understandable, now that I look through it it might be a little overcomplicated but )

[AntiSpiral]

1 hour ago, Haro said:

Well just looking at the boards images, you wont really know much about the vrm, if you want to know more about whatever a board uses, you  can watch a pcb breakdown, made by buildzoid, and those are quite detailed if you want to learn more about vrm and/or find out what a board uses for it's vrm. 

But yea Buildzoid does pcb break downs and you can learn quite a bit about vrm from him.  

Or for a more simplified one, hardware unboxed does reviews about boards and checks their vrm temps. 

Ohh thanks! I will check his channel indeed 

[AntiSpiral]

50 minutes ago, Mateyyy said:

Talking in very general terms - the number of chokes present around the CPU socket is generally a decent enough indication of how good the power delivery is on a board. That should give you an idea of how many MOSFETs (or more commonly just called phases) are present underneath those heatsinks.

 

Now, more phases/MOSFETs doesn't necessarily mean better, or at least not in terms of current handling capability - what really matters is what is actually underneath those heatsinks. You could have however many phases, but if they're just some crappy discrete MOSFETs underneath, that VRM is still going to be outperformed by a setup with half the phases but using good power stages.

 

Finding the actual components used is often quite a bit trickier. Lately, Gigabyte and MSI have been mentioning roughly what they use on the actual board's page, especially on their mid to high-end offerings.

  Reveal hidden contents

 

They don't mention the exact power stages that are used (NCP302155 in this case), but "DR. MOS 55A" is good enough, imo.

Basically, each power stage is rated for 55A of current handling (in theory), and "Dr. MOS" means that they're "dumb" power stages. They don't feature any sort of thermal or current monitoring, but do have the basic functionality of shutting down when overheating thanks to a simple flag.

  Reveal hidden contents

 

Again, the exact component choice isn't mentioned (ISL99390s), but they do let us know that they are smart power stages rated for 90A of current handling.

90A is about as high-end as you're going to get with power stages, when it comes to current handling. That's not to say that they are the be all and end all though - realistically speaking, 70A stages should be just as good, since their efficiency curves are, for the most part, very similar.

 

The fact that they're smart power stages means that they have current and temperature sensing built-in. What this means to you is more accurate VRM readings when you open up your hardware monitoring software of choice (ideally HWiNFO64).

Then there's other manufacturers like ASUS which will at most mention "Dr. MOS" regarding the VRM, and that's about it.

 

Also, one thing I mentioned a few times above was heatsinks - they're also very important. More surface area = more better, and less random plastic junk also = more better.

I think MSI's been the best at this lately, where they've been making the rear IO cover out of metal as part of the heatsink.

On the other hand, there's boards like the B550M Aorus Pro which will have plastic rear IO covers acting pretty much like heat insulators - not letting any incidental airflow in, and not letting the heat put out by the MOSFETs out. That's no bueno.

 

I would recommend looking through Buildzoid's PCB breakdowns, where he also talks about boards' power deliveries in detail, among other components:

https://www.youtube.com/playlist?list=PLpS0n7xxSadV6Gkwzv928N1MT68Nd1muu

Reviewers like Hardware Unboxed also do share details about the VRMs on boards they review, along with thermal testing. 

 

(hopefully this is somewhat understandable, now that I look through it it might be a little overcomplicated but )

First of all, THANK YOU for the amount of effort on this, honestly!
 

I see that the depth around VRM is quite extense, but as far as I can know it's always related with overclocking usage. Right now I'm looking for a good/decent board for a 3900X where there will be no OC at all. I saw on a GamersNexus video that the B550 Aorus Elite is pretty fucking good and it cost under 150€; so that might be the way to go

[Mateyyy]

5 minutes ago, AntiSpiral said:

Right now I'm looking for a good/decent board for a 3900X where there will be no OC at all. I saw on a GamersNexus video that the B550 Aorus Elite is pretty fucking good and it cost under 150€; so that might be the way to go

The B550 Aorus Elite is good, but I'd also take a look at MSI's B550-A Pro and ASUS' TUF B550(M)-Plus (both the ATX and mATX versions are the same, save for the missing PCIe slots on the mATX because of space constraints). 

The VRMs on them are at least just as good, but feature-wise I think they're ahead of the Aorus Elite in a few aspects, depending on what you're after (front panel Type-C, rear USB ports, etc.).

 

Also, if you do go with the Gigabyte board, make sure it's the ATX, not the mATX B550M variant. The VRMs on the mATX Aorus Elite and Aorus Pro are very different from their full-sized ATX counterparts, and not in a good way.

[AntiSpiral]

3 minutes ago, Mateyyy said:

The B550 Aorus Elite is good, but I'd also take a look at MSI's B550-A Pro and ASUS' TUF B550(M)-Plus (both the ATX and mATX versions are the same, save for the missing PCIe slots on the mATX because of space constraints). 

The VRMs on them are at least just as good, but feature-wise I think they're ahead of the Aorus Elite in a few aspects, depending on what you're after (front panel Type-C, rear USB ports, etc.).

 

Also, if you do go with the Gigabyte board, make sure it's the ATX, not the mATX B550M variant. The VRMs on the mATX Aorus Elite and Aorus Pro are very different from their full-sized ATX counterparts, and not in a good way.

My plan A was buying the MSI A-PRO. I don't think the client would have use of that much connectivity, but it's also 10€ cheaper than the Aorus (not that much tbh)

 

About the size is something that we will find out this afternoon, because maybe he rather have a smaller case and in that case I'd have to check for a MATX mobo . So thanks in advance for that info; I'll stay away from MATX Aorus