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can 6 phase VRM boards handle 3900X? would like feedback from people who tried it

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Based on what proof, exactly?

Yes look on the VRM Tier list nojuan999 posted a little before. There you can see it right at the top and all mainboards lexluthermiester posted are below that. Or look for the technical details of the used power stages and you will find it also...
 
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Yes look on the VRM Tier list nojuan999 posted a little before. There you can see it right at the top and all mainboards lexluthermiester posted are below that. Or look for the technical details of the used power stages and you will find it also...
You're not proving your point. That list was made by some dude who is not what can be considered a credible source. All you're doing is expressing opinion without any merit. The OP asked for ITX motherboards which meet certain requirements. All of the boards presented, regardless of your opinions, meet stated requirements and are built by well known and well regarded companies who have strict QA standards. Every one of them support the 3900X and will do so readily.
 
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You can go into detail about different VRMs but usually its simple if the motherboard manufacturer has the the cpu in their CPU Support List then it will work.
 
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Benchmark Scores Faster than yours... I'd bet on it. :)
You can go into detail about different VRMs but usually it simple if the motherboard manufacturer has the the cpu in their CPU Support List then it will work.
Yes and No. History, years of AMD FX and throttling at stock speeds with many boards, tells us otherwise. We've see it with Ryzen/R2/R3 already with budget and old chipset boards and big chips. Works and works properly are two distinct things. That said, it isn't all about phase count either... the bits below matter!!!

I'm not saying anything about the board chosen or whatnot, but just this blanket statement above.
 
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Yes and No. History, years of AMD FX and throttling at stock speeds with many boards, tells us otherwise. We've see it with Ryzen/R2/R3 already with budget and old chipset boards and big chips. Works and works properly are two distinct things. That said, it isn't all about phase count either... the bits below matter!!!

I'm not saying anything about the board chosen or whatnot, but just this blanket statement above.

No manufacturer is perfect and you can find specific problems on all of them. The support list is there for a reason as for my so called blanket statement it comes in two parts the first one witch you anwserd and the second one you ignored.
 
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Based on what proof, exactly?
Based on the VRM. The VRM itself is the proof. 6x 60amp phases on
6 true phases. The VRMs are also cooled, unlike the 6 fake VRMs on as rock boards.
 
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May I ask why not?

The NVMes can heat up quite a bit in confined spaces. Take my M1 for example; there's no room behind the board even if there is a cutout for the drive, since that side of the case doesn't have any clearance between the back of the mobo tray and the removable aluminium panel. The flash might like it hot, but the controllers don't.

The solution in a conventional case is to use a M.2 heatsink, but that still needs airflow, and in cases like the Node 202 and SG05/13 I just really don't see it being a good idea long term.

If there's something that the Aorus board does well, it's the combined PCH and M.2 heatsink. I've built twice with this board and it's handled SATA M.2 and NVMe M.2 excellently.
 
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Benchmark Scores Faster than yours... I'd bet on it. :)
SATA M.2 doesn't typically need additional cooling.

That said, unless you really have a heater and sustain writes, it isn't a huge issue...

... I get your point though.
 
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The NVMes can heat up quite a bit in confined spaces. Take my M1 for example; there's no room behind the board even if there is a cutout for the drive, since that side of the case doesn't have any clearance between the back of the mobo tray and the removable aluminium panel. The flash might like it hot, but the controllers don't.

The solution in a conventional case is to use a M.2 heatsink, but that still needs airflow, and in cases like the Node 202 and SG05/13 I just really don't see it being a good idea long term.

If there's something that the Aorus board does well, it's the combined PCH and M.2 heatsink. I've built twice with this board and it's handled SATA M.2 and NVMe M.2 excellently.

Fair enough, you're talking about extremely confined cases.
 
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NVMe drives need air flow...
I just did some quick test.

I have no case and so I have a case fan (120mm 750~850rpm) upon VRM and around socket that blows air to NVMe drive also. X570 AorusPro has first m.2 slot above GPU and next to VRM/CPU socket and has a "heatsink" also.
With the fan on, temp of drive is around 32~34C. I removed the fan, keep broswing and check it 15mins later. Drive temp was climped to 46C and it was slowly still increasing. And it wasnt even doing anything serious. m.2 slot heatsink was warm enough...

SATA m.2 drives would be a different story... but NVMe need air flow.
 
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Those are the only two 4xx series boards i'm looking at. going to avoid asrock like the plague this time around due to their junk VRM.
That is an opinion. Not a very good one. You too are referencing a list made by some dude who has no credibility. There are no testing sources or methods listed, no evidence or information that proves any conclusion.
 
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the plot thickens. turns out that my 650W gold seasonic SFX PSU was a dud, it was not able to provide adequate power but at the same time wasn't shutting off either. the gigabyte B450 ITX board works fine with the 3900X. after i got a corsair SF750 PSU (on sale for $145 at amazon germany), that 3900X is hitting 7000+ in cinebench R20 consistently and without fail. adobe premiere render times are now consistent on every run. the CPU is no longer s**ing its' pants.

this is my second, back to back, bad seasonic experience. my main desktop use to have a seasonic 1000W "prime ultra" titanium PSU. it also had trouble delivering power and sometimes would cause my computer to turn on by itself in the middle of the night. dead giveaway that something was wrong with it.

case closed. thanks for all your input guys. also, no more seasonic for me.

That is an opinion. Not a very good one. You too are referencing a list made by some dude who has no credibility. There are no testing sources or methods listed, no evidence or information that proves any conclusion.
6 low quality power phases running on a 3 phase controller with no doublers. the phases were just hooked up in parallel. that means no load/heat balancing. and the cherry on top is that the phases are not cooled well at all.

if you are running a stock 8 core or smaller CPU, it's probably fine. if you want to OC said 8 core CPU on it or run 12 or 16 core CPU on it, that board will not work well. it probably won't die but it will throttle like crazy to prevent its' own death.
 
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i have the gigabyte I x570 aorus pro wifi (ITX) ( yeah its x570& has a fan) but my system runs with stock prism cooler with 3900x and no issues...
but you have upgradabiltiy to Gen4 GPUs and SSDs, you think Nvidias RTX 3000 AMPEARE isnt goinna be 4.0?//

and it is a full 8 phase vrm


best board for the money imo
 
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i have the gigabyte I x570 aorus pro wifi (ITX) ( yeah its x570& has a fan) but my system runs with stock prism cooler with 3900x and no issues...
but you have upgradabiltiy to Gen4 GPUs and SSDs, you think Nvidias RTX 3000 AMPEARE isnt goinna be 4.0?//
it turned out that my issue was the PSU, not the board. the gigabyte B450 can run PCI E 4 as well if you use an older BIOS. i'm running and MSI E 4.0 SSD on it now. the PCI E slot is also capable of PCI E 4 on this board.

having said that, i would give up PCI-E 4 to not have a fan in a heart beat.
 
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the plot thickens. turns out that my 650W gold seasonic SFX PSU was a dud, it was not able to provide adequate power but at the same time wasn't shutting off either. the gigabyte B450 ITX board works fine with the 3900X. after i got a corsair SF750 PSU (on sale for $145 at amazon germany), that 3900X is hitting 7000+ in cinebench R20 consistently and without fail. adobe premiere render times are now consistent on every run. the CPU is no longer s**ing its' pants.
Thats very nice to hear!
Do you think you can provide a HWiNFO screenshot during R20 run now. I was interested and hoping to see one with the old PSU also (that is when you had the issue), but thats ok...
Like this

HWiNFO_30_01_2020.png

And one with idling/browsing...(30 min)

HWiNFO_28_01_2020b.png

Are you not running latest BIOS for your board? You should if not...

1. latest BIOS (AGESA 1.0.0.4 B)
2. latest chipset drivers straight from AMD (not board vendor)
3. Win10 v1909
4. 1usmus universal power plan for Ryzen

...for best boosting (all core), and optimal core loading (single threaded and low/middle loads)

IMO the X570 chipset fan "issue" is exaggerated. Mine never spins, but I have a case fan (750~850rpm) next to it, no case. When I test it, was silent enough even at 2-3000rpm. But now doesnt matter, the GPU has completely cover it, and you can see temp in those screenshots hovering around 40C.

20200129_202629743_iOS.jpg
 
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I just wanna say, I've taken an 1800X to 4.1 (1.4V) on an MSI B350 PC MATE before (4-phase) with a fan on the VRM heatsink. That was using over 200W in stress, the board took it like a champ. Now, I'm not saying that I recommend you do that, especially if you're planning on doing long-term work, but good airflow on the VRM heatsink/spreader really makes the difference.

I have my 3950X on Asrock X570M Pro4. This board isn't known for a Stellar VRM, but it's doing just fine (though I limit PPT to 105W sustained & have plenty of airflow).

If you had to ask me, I'd say the 3900X would be fine on even a budget B450 if you had good airflow & wasn't in the habit of pumping him at 100% load 24/7. Small ITX case? Probably not such a good idea. Anyway YMMV. I love PBO because I can configure the power usage (and thus thermal stress on the VRM) of the processor on the fly. You could do something similar with the 3900X, it's intelligent enough to maintain aggressive boost clocks in lightly threaded, bursty workload, but if you load up all 24 threads; it'll reign in the power usage. 3900X and 3950X are 146W PPT afaik.

IMO the X570 chipset fan "issue" is exaggerated. Mine never spins, but I have a case fan (750~850rpm) next to it, no case. When I test it, was silent enough even at 2-3000rpm. But now doesnt matter, the GPU has completely cover it, and you can see temp in those screenshots hovering around 40C.

I agree, but I wouldn't hear mine even at 5K on account of the 3x 3000 RPM 140MM PPCs lol. I'm in the minority when I say fan noise is comforting to me? Probably an Autism thing. :/

you think Nvidias RTX 3000 AMPEARE isnt goinna be 4.0?//
It will likely be 4.0. But whether it benefits in gaming from that, is another story entirely.
 
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the phases were just hooked up in parallel.
Even if true, which is doubtful, there's nothing wrong with that electrically and electronically.
that means no load/heat balancing.
And how do you reach that conclusion?
and the cherry on top is that the phases are not cooled well at all.
That's just flat out wrong. Every one of those boards have heatsinks on the VRM's

However, you solved your problem with your existing board and a new PSU.
 
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I just wanna say, I've taken an 1800X to 4.1 (1.4V) on an MSI B350 PC MATE before (4-phase) with a fan on the VRM heatsink. That was using over 200W in stress, the board took it like a champ. Now, I'm not saying that I recommend you do that, especially if you're planning on doing long-term work, but good airflow on the VRM heatsink/spreader really makes the difference.

I have my 3950X on Asrock X570M Pro4. This board isn't known for a Stellar VRM, but it's doing just fine (though I limit PPT to 105W sustained & have plenty of airflow).

If you had to ask me, I'd say the 3900X would be fine on even a budget B450 if you had good airflow & wasn't in the habit of pumping him at 100% load 24/7. Small ITX case? Probably not such a good idea. Anyway YMMV. I love PBO because I can configure the power usage (and thus thermal stress on the VRM) of the processor on the fly. You could do something similar with the 3900X, it's intelligent enough to maintain aggressive boost clocks in lightly threaded, bursty workload, but if you load up all 24 threads; it'll reign in the power usage. 3900X and 3950X are 146W PPT afaik.



I agree, but I wouldn't hear mine even at 5K on account of the 3x 3000 RPM 140MM PPCs lol. I'm in the minority when I say fan noise is comforting to me? Probably an Autism thing. :/


It will likely be 4.0. But whether it benefits in gaming from that, is another story entirely.

Its fun to watch the convo. Lots of different opinions here.
Some facts which is good and some skewing from the topic. No probs.

Id pit my Asus Rog B450-I to a 3900X test while is has IR3553 on 6 phases.

The issue is we are advertised 105w. This wattage is only accurate to the highest p-state of the cpu under a full load.

While all of us will see higher wattage usage while using even defaul PBO.

But Id pit my Asus Rog B450-I to the test running a 3900x.
6 IR3553 VRMs on 6 phase would be plenty even if you could manage to pull 200w.

Then cooling.
Well if you're not scared to run your cpu at 85c, why would it bother one to see VRMs getting that warm? Most VRMs operate at 100c as thats the design. Wont hurt it. Cool it? Yes you should. Some of that heat makes its way through the board right to the cpu and visa versa.

3900x. 6 vrms. Meh why not. This is no FX 220w cpu. Should be no issue for any one.
 
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The issue is we are advertised 105w. This wattage is only accurate to the highest p-state of the cpu under a full load.

While all of us will see higher wattage usage while using even defaul PBO.
105W is the TDP, not the power consumption though?. While broadly related, they are not =.

AFAIK for Ryzen it is:

45W TDP = 60W PPT (socket power)
65W TDP = 88W PPT
95W TDP = 125W PPT
105W TDP = 146W PPT

With 3rd gen parts, all of the SKU seem to be at, or close to, their PPT limits while the previous gen (in my experience) are closer to "TDP".

Anyway, 100C VRM is fine for the MosFETs, yes, but my main concern was actually Aluminum electrolytic capacitors around the VRM/socket, which really don't appreciate high temps and can be problematic if they're in an airflow dead-zone. Anyway, YMMV, my standards are pretty high because I need my systems to run 24/7 at 100% load.
 
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105W is the TDP, not the power consumption though?. While broadly related, they are not =.

AFAIK for Ryzen it is:

45W TDP = 60W PPT (socket power)
65W TDP = 88W PPT
95W TDP = 125W PPT
105W TDP = 146W PPT

With 3rd gen parts, all of the SKU seem to be at, or close to, their PPT limits while the previous gen (in my experience) are closer to "TDP".

Anyway, 100C VRM is fine for the MosFETs, yes, but my main concern was actually Aluminum electrolytic capacitors around the VRM/socket, which really don't appreciate high temps and can be problematic if they're in an airflow dead-zone. Anyway, YMMV, my standards are pretty high because I need my systems to run 24/7 at 100% load.

But we run around like boards are failing 105w 146w ppt on 4+1, which you actually don't really see happenening much. At least I havent read about many boards VRM failing.

105w is a Thermal design power. 146w is energy usage.

Not really sure what the concerns are.... People run 105w chips on 4 VRMs a lot more often than on boards with 6 VRMs.

I only find the conversation curious, while these chips run pretty cool and use quite a bit less PPT than previous generations. And they where supporting 125w chips on 4 VRMs then..... We all had the same convo then as we do now.

Again, Id pit my 6 VRMs to a 3900x, but Im well aware of how to cool my hardware.
 
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But we run around like boards are failing 105w 146w ppt on 4+1, which you actually don't really see happenening much. At least I havent read about many boards VRM failing.

105w is a Thermal design power. 146w is energy usage.

Not really sure what the concerns are.... People run 105w chips on 4 VRMs a lot more often than on boards with 6 VRMs.

I only find the conversation curious, while these chips run pretty cool and use quite a bit less PPT than previous generations. And they where supporting 125w chips on 4 VRMs then..... We all had the same convo then as we do now.

Again, Id pit my 6 VRMs to a 3900x, but Im well aware of how to cool my hardware.
I agree tbh, the VRM argument is a bit over-exaggerated. Gigabyte actually 'certified' their Heatsink-less B350 D3V with 4 phases for the 3950X on the latest bios. (DISCLAIMER: Don't use this board with a 3950X, the VRM would throttle it a LOT). People seem to think that motherboards are going to explode into flames if they draw a bit more power. In reality, most of these boards are going to trigger PROCHOT EXT and throttle the CPU (it might not even be by a lot). If Gigabyte certified that, then they are OK with using 3950X on it for warranty period.

Most B450 boards (maybe all) are perfectly adequate for 3800X for full use, and 3900X and 3950X for use with reasonable airflow if you don't want throttling.
 
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I dont think a tone said they will explode...but the point is to be careful. If you are buying a HCC chip, it makes sense to pair it with a more robust vrm so you can get the most out of it (read: no throttling, better chance to achieve rated boost...and for longer, etc).

Just because a HCC chip is on the compatibility list it will work 'properly' isn't The Gospel. We've seen issues like this from the same company a couple gens ago. Shrimp knows... hes an fx guy. Many boards couldnt handle the 'octo' fx without throttling or having to resort to mods/active cooling to prevent throttling. We see x570 is, overall, a more robust vrm platform and for good reason. There are plenty of x470 boards that can do it.. but once you get to b450 on down, id be a bit leary especially if I wanted the most out of the cpu.
 
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it turned out that my issue was the PSU, not the board.

Nice that you found the problem in your case :)

That is an opinion. Not a very good one. You too are referencing a list made by some dude who has no credibility.

Yes and that is also an opinion or did you prove that this list is wrong? It's easy to request proof from others but not providing any by yourself.

Actually I didn't claim, that one of the posted boards is not able to run a Ryzen 3900X. I only gave some advice which of these boards, in question their VRMs, is more or less capable to run a Ryzen 3900X.
Sure every board which has the Ryzen 3900X on its support list will run this CPU, no question at all, but the other question is, on which of these boards will it run better or let's say does it has more headroom. And regarding this point everyone can prove this statement.

1, Regarding number of phases:
The VRM must be capable of handling the current load. That can be done with any of those solutions out there. You can do it via fake phases, that is every phase has its components twice, or even three times like Asus did in their latest X570 boards, or you can do it via doublers or do it with real phases. All of these solutions make the VRM capable of handling more current and not getting too hot. But current handling is only one problem here. Another is a smooth voltage output and less ripple. This problem cannot be solved with twin, triple or doubled phases but with a higher number of real phases or with a higher switching PWM controller. As higher switching decreases the efficiency of the VRM the solution to add more phases is better here. So ideally your VRM has for example an 8-phase capable PWM controller and you have 8 real phases. If one of those phases are discharging another of the 8 can set in with an offset and voltage drop gets smoothed. With 4 fake phases or even less and twice components there are only 4 or 3 in the game of charging/discharging and with 4 doubled phases, the PWM switching freq gets halved which downgrades voltage output also and makes transient response worse.
But if your VRM is too oversized for the daily load, the efficiency will also be a little worse. So it has to match the used cpu and if you are planning to oc, but we are talking here of an Ryzen 3900X, so not the smallest AMD cpu.

2, Regarding the used MOSFETs
Every VRM consists of High-Side and Low-Side MOSFETs and they both have a specific max current capability. Some boards have separate chips other boards have one chip as package of High/Low-Side MOSFET included, others include also the Gate Driver. Each MOSFET High/Low-Side has to handle a portion of the current load. How much determines the duty cycle of the PWM signal. The smaller the duty cycle the more current have to handle the Low-Side MOSFETs. As the duty cycle calculates to Vout/Vin you see that the less the cpu output voltage for a given input voltage is the smaller is the duty cycle and the more current have to handle the Low-Side MOSFETs. So they must be the better chips in the VRM or those chips that have the better current capability compared to the High-Side MOSFETs. So you can approximately calculate the VRMs current capability in counting the number of Low-Side FETs and multiply it with their current capability.
Additionally the power losses in the MOSFETs result in increasing temps. Power Losses are mainly conduction losses and switching losses. First is dependent of the MOSFETs Drain to Source resistance, can be found in their data sheets, second depends of the switching freq. Both result in increasing temps and the amount of heat, the MOSFET rises per W power loss, depends of the MOSFETs thermal resistance, can alo be found in their data sheets. The hotter the MOSFET the less its current handling capability.
So the less Drain to Source resistance, the less thermal resistance and the less switching loss, the less heat is produced and the better the efficiency and current capability.

3, The Boards
If you look for example at these posted boards:
- Asrock Fatality B450 Gaming ITX
- Asrock Fatality X470 Gaming ITX
- Gigabyte B450I Aorus
- Asus ROG STRIX B450-I Gaming
- Asus ROG STRIX X470-I Gaming
- MSI B450-I Gaming Plus

The Asrock boards:
Both have 6 fake phases, that is only 3 real phases and every of these 3 phases has its components twice. According to a list from Hardwareluxx, the B450 Gaming uses for High/Low-Side MOSFETs either the Onsemi FDPC5030 or the Sinopower SM7341EH . I think this is dependent of the board's revision. Assuming they use both the Onsemi chip, this chip consists of one package with High-Side and Low Side MOSFET included. Here is the data sheet:


The Ryzen 3900X draws 100A to 140A (Spikes) with stock setting, no oc here. At 100A every stage (3x2) has to handle 100/6=16,7A. With spikes up to 140/6=23.3A. With the data from the data sheet you can calculate the power losses in the MOSFETs (mainly conduction losses, switching losses and charging losses) to approximately (assuming 12V input/1.42V output, 300kHz switching freq):
Power Loss@16,7A=1.14W
Power Loss@23,3A=2.1W

According the data sheet, the chip has a thermal resistance junction to ambient of 55 degrees C/W, that is 1W power loss in the MOSFET results in 55 degrees celsius heat against ambient. So if ambient is about 25 degrees the junction temp will result in 25+55=80 degrees celsius.

1.14W power loss corresponds to 1.14x55=62.7C
2.1W power loss results in 2.1x55=115.5C

At an ambient of 25 degrees it will result in the first case to 62.7+25=87.7C and in the second case to 115.5+25=140.5C junction temp. The max junction temp of this chip is 150 degrees, so a heatsink is definitelyx needed to cool the MOSFETs down.

The Gigabyte B450I Aorus:
Gigabyte uses 4 real phases with IR3556 stages. The IR is a package with Low and High Side MOSFET and gate driver included. It's a 50A stage and as they don't use doubled or twin phases each phase has to handle 100/4=25A up to 140/4=35A.


1580328817500.png


Fortunately they have a power loss graph of the IR3551 as there is no data sheet of the 3556, but both are IR 50A stages.
The thermal resistance junction to ambient is here 21.1 C/W, that's way better than the Asrock stages thermal resistance. The power loss at 25A is at approximately 2.5W, so at 25 degrees ambient it would result in 2.5x21.1+25=77.75 degrees junction temp.
The power loss at 35A is at 4.5W, so 4.5x21.1+25=119.95C degrees junction temp. So although it only uses 4 power stages here it stays cooler than the two Asrock boards because of the thermal resistance of the used IR stages. Additional those IR stages have the Gate Driver included, which dissipates additional power loss, so they are very efficient.

The Asus B450I Gaming board:
6 real phases of IR3556 stages, the same Gigabyte uses but now 2 more. Each phase has to handle 16.7A up to 23.3A, the same as Asrock here.
Power loss at 16.7A at about 1.6W result in 1.6x21.1+25=58.76 degreees junction. Power loss at 23.3A approx 2.3W result in 2.3*21.1+25=73.53 degrees junction temp, so the best far now.

The Asus X470 board:
The same VRM as the B450I board.

The MSI B450I Gaming:
6 real phases of IR3555 power stages. Those are 60A power stages.

1580391220079.png


As there is no data sheet of the IR3555 here is one of the IR3550, also a 60A IR stage:


Thermal resistance junction to ambient is here 20.2 C/W. The power loss at 16.7A is at approx 1.3W results in 1.3x20.2+25=51.26 degrees junction temp. Power Loss at 23.3A is at 2W, results in 2x20.2+25=65.4 degrees junction.


All those temps are without heatsink, the chips mounted on a 1 in2 pad of 2 oz copper, as stated in their data sheets to get it comaprable. With heatsinks all of these boards are capable to handle a stock Ryzen 3900X, but nevertheless you can make a rating which VRM will be more or less capable or efficient, and this is my personal rating from top to bottom:

1, MSI B450I Gaming
2, The two Asus boards
3, The Gigabyte board
4, The two Asrock boards

And I would stay away from the Asrock boards if I had to choose a new B450/X470 board and if I have a Ryzen 3900X/3950X to put in. If I would own such a board already it will do fine also, no question, but with less headroom than the others.
 
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@JackCarver
That was an impressive, very technical display. If the OP had not already stated that the problem was their PSU and not the motherboard, I would be happy to discuss your presentation.
 
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