• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

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

Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
hello,

i'm looking to build an ITX computer with a 3900X. i would like to use a B450/X470 board because they don't have any chipset fans. i have no use for PCI E 4 and don't need the extra heat and noise in this small case. however, i'm not sure if any of the existing B450/X470 boards can handle a 3900X going HAM while editing video or occasional gaming.

it looks like the 4xx boards with the best VRM are the asus B450 and MSI B450. both have 6 phase, 60A/phase VRMs. i'm not sure how the math works here but i do know that the 3900X has a 150W hard power limit. if i understand it correctly, the VRMs will work at around 1.2V, multiplied by 60A and then by 6 (# of VRMs). so, 1.2V x60A x6 = 432W max power delivery? does that mean that the B450 board will be OK with it long term?

i don't plan on hardcore OCing, but i will probably flip on PBO.

any ideas? or better yet, is anyone running a 3900X on a 6 phase VRM board?
 
Joined
Aug 6, 2017
Messages
7,412 (3.05/day)
Location
Poland
System Name Purple rain
Processor 10.5 thousand 4.2G 1.1v
Motherboard Zee 490 Aorus Elite
Cooling Noctua D15S
Memory 16GB 4133 CL16-16-16-31 Viper Steel
Video Card(s) RTX 2070 Super Gaming X Trio
Storage SU900 128,8200Pro 1TB,850 Pro 512+256+256,860 Evo 500,XPG950 480, Skyhawk 2TB
Display(s) Acer XB241YU+Dell S2716DG
Case P600S Silent w. Alpenfohn wing boost 3 ARGBT+ fans
Audio Device(s) K612 Pro w. FiiO E10k DAC,W830BT wireless
Power Supply Superflower Leadex Gold 850W
Mouse G903 lightspeed+powerplay,G403 wireless + Steelseries DeX + Roccat rest
Keyboard HyperX Alloy SilverSpeed (w.HyperX wrist rest),Razer Deathstalker
Software Windows 10
Benchmark Scores A LOT
good 6 phase ? of course.
 
Joined
May 30, 2018
Messages
1,890 (0.89/day)
Location
Cusp Of Mania, FL
Processor Ryzen 9 3900X
Motherboard Asus ROG Strix X370-F
Cooling Dark Rock 4, 3x Corsair ML140 front intake, 1x rear exhaust
Memory 2x8GB TridentZ RGB [3600Mhz CL16]
Video Card(s) EVGA 3060ti FTW3 Ultra Gaming
Storage 970 EVO 500GB nvme, 860 EVO 250GB SATA, Seagate Barracuda 1TB + 4TB HDDs
Display(s) 27" MSI G27C4 FHD 165hz
Case NZXT H710
Audio Device(s) Modi Multibit, Vali 2, Shortest Way 51+ - LSR 305's, Focal Clear, HD6xx, HE5xx, LCD-2 Classic
Power Supply Corsair RM650x v2
Mouse iunno whatever cheap crap logitech *clutches Xbox 360 controller security blanket*
Keyboard HyperX Alloy Pro
Software Windows 10 Pro
Benchmark Scores ask your mother
Yep! Running mine on a Strix x370-f with 6 60A IR power phases and it runs on point. Just enabled PBO and it ran right up to expected performance. Still has more to give. No signs of strain on the VRMs whatsoever.
 
Joined
Aug 6, 2017
Messages
7,412 (3.05/day)
Location
Poland
System Name Purple rain
Processor 10.5 thousand 4.2G 1.1v
Motherboard Zee 490 Aorus Elite
Cooling Noctua D15S
Memory 16GB 4133 CL16-16-16-31 Viper Steel
Video Card(s) RTX 2070 Super Gaming X Trio
Storage SU900 128,8200Pro 1TB,850 Pro 512+256+256,860 Evo 500,XPG950 480, Skyhawk 2TB
Display(s) Acer XB241YU+Dell S2716DG
Case P600S Silent w. Alpenfohn wing boost 3 ARGBT+ fans
Audio Device(s) K612 Pro w. FiiO E10k DAC,W830BT wireless
Power Supply Superflower Leadex Gold 850W
Mouse G903 lightspeed+powerplay,G403 wireless + Steelseries DeX + Roccat rest
Keyboard HyperX Alloy SilverSpeed (w.HyperX wrist rest),Razer Deathstalker
Software Windows 10
Benchmark Scores A LOT
Joined
May 30, 2018
Messages
1,890 (0.89/day)
Location
Cusp Of Mania, FL
Processor Ryzen 9 3900X
Motherboard Asus ROG Strix X370-F
Cooling Dark Rock 4, 3x Corsair ML140 front intake, 1x rear exhaust
Memory 2x8GB TridentZ RGB [3600Mhz CL16]
Video Card(s) EVGA 3060ti FTW3 Ultra Gaming
Storage 970 EVO 500GB nvme, 860 EVO 250GB SATA, Seagate Barracuda 1TB + 4TB HDDs
Display(s) 27" MSI G27C4 FHD 165hz
Case NZXT H710
Audio Device(s) Modi Multibit, Vali 2, Shortest Way 51+ - LSR 305's, Focal Clear, HD6xx, HE5xx, LCD-2 Classic
Power Supply Corsair RM650x v2
Mouse iunno whatever cheap crap logitech *clutches Xbox 360 controller security blanket*
Keyboard HyperX Alloy Pro
Software Windows 10 Pro
Benchmark Scores ask your mother
that is true 6 phase and quality components
i'm a little afraid the op is talkling about 3 phase with a double on some crappy isl
Ooo yeah... that would be iffy.

EDIT: Removing bad info... I was remembering overclocking a different CPU, thinking my 3900x did over 200w when all I had to do was check my saved benches to see it was actually more like 125w. :oops: I need to not post at work, I think...
 
Last edited:

Ozymandias

New Member
Joined
Oct 23, 2019
Messages
9 (0.01/day)

I'm running a 3900X on an X370.
Admittedly it's on an VI Extreme which handles it with ease.

Also running a 3900 (non-x) on a X570 TUF.

[EDIT] Beaten to it.
 
Last edited:

tabascosauz

Moderator
Supporter
Staff member
Joined
Jun 24, 2015
Messages
7,457 (2.33/day)
Location
Western Canada
System Name ab┃ob
Processor 7800X3D┃5800X3D
Motherboard B650E PG-ITX┃B550-I Strix
Cooling PA120+T30┃AXP120x67
Memory 64GB 6000CL30┃32GB 3600CL14
Video Card(s) RTX 4070 Ti Eagle┃RTX A2000
Storage 8TB of SSDs┃1TB SN550
Display(s) 43" QN90B / 32" M32Q / 27" S2721DGF
Case Caselabs S3┃Lone Industries L5
Power Supply Corsair HX1000┃HDPlex
The Strix and MSI ITX B450s are just fine. 6 true Vcore phases with 40A and 60A PowIR respectively, IR35201.

The 3900X isn't that much a monster on power draw when not forced to run on fixed frequencies. As with anything without an active VRM fan, ensure decent airflow. PBO doesn't increase wattage much. Too many other limits in place

The Aorus ITX uses good components but the heatsink is subpar and it lacks on phases, making it a bit hot for >8 cores even with 50A PowIRs on IR35201 like the other two. The other ASRock B450 is utter trash.

These PowIRs are the top dogs of yesteryear. This X570 ITX generation is filled with brand spanking new IR TDAs and Vishay SPSes instead, but again, overkill on 3900X.
 
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
that is true 6 phase and quality components
i'm a little afraid the op is talkling about 3 phase with a doubler on some crappy isl

for reference
i'm not. the two boards i mentioned are both true 6 phase VRM boards. 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.

The Strix and MSI ITX B450s are just fine. 6 true Vcore phases with 40A and 60A PowIR respectively, IR35201.

oh damn, good call. i thought all the phases on the asus were 60A, turns out it was only the SOC VRM that's 60A. looks like i'll be buying my first ever MSI board.
 
Last edited:

tabascosauz

Moderator
Supporter
Staff member
Joined
Jun 24, 2015
Messages
7,457 (2.33/day)
Location
Western Canada
System Name ab┃ob
Processor 7800X3D┃5800X3D
Motherboard B650E PG-ITX┃B550-I Strix
Cooling PA120+T30┃AXP120x67
Memory 64GB 6000CL30┃32GB 3600CL14
Video Card(s) RTX 4070 Ti Eagle┃RTX A2000
Storage 8TB of SSDs┃1TB SN550
Display(s) 43" QN90B / 32" M32Q / 27" S2721DGF
Case Caselabs S3┃Lone Industries L5
Power Supply Corsair HX1000┃HDPlex
oh damn, good call. i thought all the phases on the asus were 60A, turns out it was only the SOC VRM that's 60A. looks like i'll be buying my first ever MSI board.

I mean, I'm not sure you'll ever even get close to 40Ax6=240A of power draw on a PB 3900X...the new TDA21472 (70A) equipped X570 boards are beginning to approach "too-good" territory, where the hardware spends the vast majority of its time in a power band where the efficiency is actually undesirable on the new smart power stages. Remember that all of these PowIRs and SPSes are rated for maximum current, and that you'll have to get within throwing distance of that number to actually achieve peak efficiency. Too overkill / too little power draw and they're actually not very efficient.

Depends on what you're after, I guess. I'll never opt for for a board that places an NVMe M.2 on the back of the board (the MSI ITX). The Strix has got two 3.0 x4s, but the second shares bandwidth with the x16 slot. MSI also has a shittier wifi card (not hard to replace) than the Aorus and Strix, as well as shittier LAN (the other two have i211), but it's not a big deal for most people. The big selling point of the Strix and MSI are the extra two true phases, which really reduce the heat on the pitifully designed heatsinks that all 3 of them have.
 
Joined
Nov 6, 2019
Messages
326 (0.20/day)
Location
Nuremberg
Processor Core i7 8700K@5 GHz
Motherboard MSI Z370 Gaming Pro Carbon
Cooling 2xEKWB Rads, EKWB Reservoir 250, Aqua Computer Kryos Next CPU Cooler, Phanteks Glacier GPU Cooler
Memory 16 GB DDR4 GSkill Trident Z 3200
Video Card(s) Asus ROG STRIX RTX 2080 O8G (GPU@2115 MHz/VRAM@7800MHz)
Storage 1x Samsung Evo 840 SSD 256, 1x WD Blue 1 TB HDD
Display(s) Asus ROG Swift PG248 1080p Display/144Hz/G-Sync
Case Fractal Design R6 with Window
Audio Device(s) Realtek onboard
Power Supply be quiet 650W Straight Power
Mouse Logitech G502
Keyboard Cherry KB
Software Win 10 Pro
Benchmark Scores FireStrike: 25953/Extreme: 13141/Ultra: 7099/TimeSpy: 11426/Superposition: 7667/CinebenchR20: 3916
Get the MSI B450I Gaming with 60A power stages. The two Ryzen 3900X/3950X have 95A-140A current draw. 95A most of the time with spikes to 140A. If you do a little overclocking it will be higher. If you look at the efficiency graph of the IR 40A and the IR 60A power stages you see, that the efficiency of the 60A stages is better with 6 phases than the efficiency of the 40A stages:

1579813434184.png


With 100A current output every phase has to handle 17A, so you are still in a very good efficiency here. Power Loss and heat dissipation is here less than 2 Watts per stage.
With the 40A stages of the Asus Board it looks like:


1579813530880.png


So with 17A per stage efficiency is not as good as with 60A stages as you can see. Power Loss is here at 2 Watts per stage. So with overclocking the 60A stages will be way better here.

Edit:
If you choose another brand then no problem, but be sure to get 60A stages.
 

Attachments

  • 1579813168102.png
    1579813168102.png
    23.5 KB · Views: 277
Last edited:
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
@tabascosauz i was going to say that, according to my memory, the bigger power stages should be more efficient overall even at low power draw, and therefor output less heat in to the ITX chassis i'll be putting this in. @JackCarver posted the actual efficiency charts just above me. the difference is small, the 60A stages are about 2%-3% more efficient, but they have more headroom.

looks like a 3900X with PBO will have the 40A stages running at about 50% load, that will probably torpedo the life of the board. 60A is probably the better choice here.

i'll probably be replacing the heatsink on whichever board i get with a proper one.
 

tabascosauz

Moderator
Supporter
Staff member
Joined
Jun 24, 2015
Messages
7,457 (2.33/day)
Location
Western Canada
System Name ab┃ob
Processor 7800X3D┃5800X3D
Motherboard B650E PG-ITX┃B550-I Strix
Cooling PA120+T30┃AXP120x67
Memory 64GB 6000CL30┃32GB 3600CL14
Video Card(s) RTX 4070 Ti Eagle┃RTX A2000
Storage 8TB of SSDs┃1TB SN550
Display(s) 43" QN90B / 32" M32Q / 27" S2721DGF
Case Caselabs S3┃Lone Industries L5
Power Supply Corsair HX1000┃HDPlex
@tabascosauz i was going to say that, according to my memory, the bigger power stages should be more efficient overall even at low power draw, and therefor output less heat in to the ITX chassis i'll be putting this in. @JackCarver posted the actual efficiency charts just above me. the difference is small, the 60A stages are about 2%-3% more efficient, but they have more headroom.

looks like a 3900X with PBO will have the 40A stages running at about 50% load, that will probably torpedo the life of the board. 60A is probably the better choice here.

i'll probably be replacing the heatsink on whichever board i get with a proper one.

You don't need to go those kinds of lengths; this isn't AM3+. Just get some air moving over the heatsink and you'll be plenty fine.

What case is this going into, and what is the 3900X cooled with? Anything larger and traditionally laid out like a QBX or H200i, just treat it as you would any other ATX build.
 
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
You don't need to go those kinds of lengths; this isn't AM3+. Just get some air moving over the heatsink and you'll be plenty fine.

What case is this going into?

fully watercooled node 202. see attached picture.

it's currently running an overclocked 8600k + RTX 2080 super.
 

Attachments

  • IMG_8798.jpg
    IMG_8798.jpg
    2.5 MB · Views: 536
Joined
Nov 6, 2019
Messages
326 (0.20/day)
Location
Nuremberg
Processor Core i7 8700K@5 GHz
Motherboard MSI Z370 Gaming Pro Carbon
Cooling 2xEKWB Rads, EKWB Reservoir 250, Aqua Computer Kryos Next CPU Cooler, Phanteks Glacier GPU Cooler
Memory 16 GB DDR4 GSkill Trident Z 3200
Video Card(s) Asus ROG STRIX RTX 2080 O8G (GPU@2115 MHz/VRAM@7800MHz)
Storage 1x Samsung Evo 840 SSD 256, 1x WD Blue 1 TB HDD
Display(s) Asus ROG Swift PG248 1080p Display/144Hz/G-Sync
Case Fractal Design R6 with Window
Audio Device(s) Realtek onboard
Power Supply be quiet 650W Straight Power
Mouse Logitech G502
Keyboard Cherry KB
Software Win 10 Pro
Benchmark Scores FireStrike: 25953/Extreme: 13141/Ultra: 7099/TimeSpy: 11426/Superposition: 7667/CinebenchR20: 3916
@tabascosauz i was going to say that, according to my memory, the bigger power stages should be more efficient overall even at low power draw, and therefor output less heat in to the ITX chassis i'll be putting this in. @JackCarver posted the actual efficiency charts just above me. the difference is small, the 60A stages are about 2%-3% more efficient, but they have more headroom.

looks like a 3900X with PBO will have the 40A stages running at about 50% load, that will probably torpedo the life of the board. 60A is probably the better choice here.

i'll probably be replacing the heatsink on whichever board i get with a proper one.

With stock settings the 40Amps stages will be enough, but with oc and spikes to 200Amps for example every stage has to handle 33,33A. The 60A stages are still in the 90s here with about 18W heat dissipation. The 40A are at 86% with 36W heat dissipation. So a good heatsink is here definitely necessary.
 

tabascosauz

Moderator
Supporter
Staff member
Joined
Jun 24, 2015
Messages
7,457 (2.33/day)
Location
Western Canada
System Name ab┃ob
Processor 7800X3D┃5800X3D
Motherboard B650E PG-ITX┃B550-I Strix
Cooling PA120+T30┃AXP120x67
Memory 64GB 6000CL30┃32GB 3600CL14
Video Card(s) RTX 4070 Ti Eagle┃RTX A2000
Storage 8TB of SSDs┃1TB SN550
Display(s) 43" QN90B / 32" M32Q / 27" S2721DGF
Case Caselabs S3┃Lone Industries L5
Power Supply Corsair HX1000┃HDPlex
fully watercooled node 202. see attached picture.

it's currently running an overclocked 8600k + RTX 2080 super.

@terroralpha Is that a Z390 PG/ac? If you're not having any thermal problems overclocked on that toasty power delivery setup, you won't have any trouble here. It really isn't that beefy, save for the heatpipe which is of limited usefulness in that application. But short of some hard 9900K OC it's just fine with some airflow; same goes here for the 6-phase MSI. Even if you replace the Vcore heatsink with aftermarket copper ones a la AM3, if your case is airflow limited it won't do you a lot of good. A good ol' fan goes a long, long way.

@JackCarver Also, I'm not sure where this "200A spikes" number is coming from. Do you own a Zen 2 platform? Stock EDC (short-term) limit is 140A; PBO won't take his chip far past that, you have to run fixed freq for that. And like I've said a billion times, fixed freq is not the way to go.
 
Last edited:
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
Is that a Z390 PG/ac? If you're not having any thermal problems overclocked on that toasty power delivery setup, you won't have any trouble here.
Yep, I had no problem with it. But that board has a beefy heatsink on the CPU VRM
 
Joined
Jul 5, 2013
Messages
25,559 (6.52/day)
hello,

i'm looking to build an ITX computer with a 3900X. i would like to use a B450/X470 board because they don't have any chipset fans. i have no use for PCI E 4 and don't need the extra heat and noise in this small case. however, i'm not sure if any of the existing B450/X470 boards can handle a 3900X going HAM while editing video or occasional gaming.

it looks like the 4xx boards with the best VRM are the asus B450 and MSI B450. both have 6 phase, 60A/phase VRMs. i'm not sure how the math works here but i do know that the 3900X has a 150W hard power limit. if i understand it correctly, the VRMs will work at around 1.2V, multiplied by 60A and then by 6 (# of VRMs). so, 1.2V x60A x6 = 432W max power delivery? does that mean that the B450 board will be OK with it long term?

i don't plan on hardcore OCing, but i will probably flip on PBO.

any ideas? or better yet, is anyone running a 3900X on a 6 phase VRM board?
Do you have a specific board in mind? If it is of sufficient quality, 6-phase power will do fine.
 
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
Do you have a specific board in mind? If it is of sufficient quality, 6-phase power will do fine.
yep, i mentioned both of them in the OP. asus B450 ITX and msi B450 ITX. will be going with the MSI
 
Joined
Jul 5, 2013
Messages
25,559 (6.52/day)
yep, i mentioned both of them in the OP. asus B450 ITX and msi B450 ITX. will be going with the MSI
You didn't mention board make or models, thus my comment. Not all B450 boards are made equal. I've seen budget models that have only 4-phase power to the CPU.
 

tabascosauz

Moderator
Supporter
Staff member
Joined
Jun 24, 2015
Messages
7,457 (2.33/day)
Location
Western Canada
System Name ab┃ob
Processor 7800X3D┃5800X3D
Motherboard B650E PG-ITX┃B550-I Strix
Cooling PA120+T30┃AXP120x67
Memory 64GB 6000CL30┃32GB 3600CL14
Video Card(s) RTX 4070 Ti Eagle┃RTX A2000
Storage 8TB of SSDs┃1TB SN550
Display(s) 43" QN90B / 32" M32Q / 27" S2721DGF
Case Caselabs S3┃Lone Industries L5
Power Supply Corsair HX1000┃HDPlex
You didn't mention board make or models, thus my comment. Not all B450 boards are made equal. I've seen budget models that have only 4-phase power to the CPU.

He said he wanted to build ITX. He said he was looking for B450. There are only 4 choices there, one of which is trash, one of which is unsuitable for >8 cores, and two that are actual contenders.

@terroralpha I hope you don't mind audio / have a better audio solution ready. MSI one is ALC887, a name I haven't seen in a long, long time.
 
Joined
Nov 2, 2013
Messages
461 (0.12/day)
System Name Auriga
Processor Ryzen 7950X3D w/ aquacomputer cuplex kryos NEXT with VISION - acrylic/nickel
Motherboard Asus ROG Strix X670E-E Gaming WiFi
Cooling Alphacool Res/D5 Combo •• Corsair XR7 480mm + Black Ice Nemesis 360GTS radiators •• 7xNF-A12 chromax
Memory 2x 32GB G.Skill Trident Z5 Neo RGB @ 6200MHz, 30-40-40-28, 1.35V (F5-6000J3040G32GX2-TZ5NR)
Video Card(s) MSI RTX 4090 Suprim Liquid X w/ Bykski waterblock
Storage 2TB WD Black SN850X ••• 2TB Corsair M510 ••• 40TB QNAP NAS via SFP+ NIC
Display(s) Alienware AW3423DWF (3440x1440, 10-bit @ 139Hz)
Case Thermaltake Core P8
Power Supply Corsair AX1600i
Mouse Razer Viper V2 Pro (FPS games) + Logitech MX Master 2S (everything else)
Keyboard Keycult No2 rev 1 w/Amber Alps and TX stabilizers on a steel plate. DCS 9009 WYSE keycaps
Software W10 X64 Pro
Benchmark Scores https://valid.x86.fr/c3rxw7
He said he wanted to build ITX. He said he was looking for B450. There are only 4 choices there, one of which is trash, one of which is unsuitable for >8 cores, and two that are actual contenders.

@terroralpha I hope you don't mind audio / have a better audio solution ready. MSI one is ALC887, a name I haven't seen in a long, long time.

Nope. Don’t care. I’m using a Bluetooth headset anyway. Even if there was no audio output at all i wouldn’t care. Thanks for the heads up though.
 

Durvelle27

Moderator
Staff member
Joined
Jul 10, 2012
Messages
6,678 (1.56/day)
Location
Memphis, TN
System Name Black Prometheus
Processor |AMD Ryzen 7 1700X
Motherboard ASRock B550M Pro4|MSI X370 Gaming PLUS
Cooling Thermalright PA120 SE | AMD Stock Cooler
Memory G.Skill 64GB(2x32GB) 3200MHz | 32GB(4x8GB) DDR4
Video Card(s) |AMD R9 290
Storage Sandisk X300 512GB + WD Black 6TB+WD Black 6TB
Display(s) LG Nanocell85 49" 4K 120Hz + ACER AOPEN 34" 3440x1440 144Hz
Case DeepCool Matrexx 55 V3 w/ 6x120mm Intake + 3x120mm Exhaust
Audio Device(s) LG Dolby Atmos 5.1
Power Supply Corsair RMX850 Fully Modular| EVGA 750W G2
Mouse Logitech Trackman
Keyboard Logitech K350
Software Windows 10 EDU x64
3900X worked just fine on my B350 Board
 
Joined
Jul 5, 2013
Messages
25,559 (6.52/day)
He said he wanted to build ITX. He said he was looking for B450. There are only 4 choices there, one of which is trash, one of which is unsuitable for >8 cores, and two that are actual contenders.
I found 6 that meet the requirements stated in the OP.
Every one of these will work well for the OP's needs.
 
Last edited:
Joined
Nov 6, 2019
Messages
326 (0.20/day)
Location
Nuremberg
Processor Core i7 8700K@5 GHz
Motherboard MSI Z370 Gaming Pro Carbon
Cooling 2xEKWB Rads, EKWB Reservoir 250, Aqua Computer Kryos Next CPU Cooler, Phanteks Glacier GPU Cooler
Memory 16 GB DDR4 GSkill Trident Z 3200
Video Card(s) Asus ROG STRIX RTX 2080 O8G (GPU@2115 MHz/VRAM@7800MHz)
Storage 1x Samsung Evo 840 SSD 256, 1x WD Blue 1 TB HDD
Display(s) Asus ROG Swift PG248 1080p Display/144Hz/G-Sync
Case Fractal Design R6 with Window
Audio Device(s) Realtek onboard
Power Supply be quiet 650W Straight Power
Mouse Logitech G502
Keyboard Cherry KB
Software Win 10 Pro
Benchmark Scores FireStrike: 25953/Extreme: 13141/Ultra: 7099/TimeSpy: 11426/Superposition: 7667/CinebenchR20: 3916
VRM wise the MSI B450I Gaming is the best.
 
Joined
Sep 3, 2019
Messages
2,965 (1.78/day)
Location
Thessaloniki, Greece
System Name PC on since Aug 2019, 1st CPU R5 3600 + ASUS ROG RX580 8GB >> MSI Gaming X RX5700XT (Jan 2020)
Processor Ryzen 9 5900X (July 2022), 150W PPT limit, 79C temp limit, CO -9~14
Motherboard Gigabyte X570 Aorus Pro (Rev1.0), BIOS F37h, AGESA V2 1.2.0.B
Cooling Arctic Liquid Freezer II 420mm Rev7 with off center mount for Ryzen, TIM: Kryonaut
Memory 2x16GB G.Skill Trident Z Neo GTZN (July 2022) 3600MHz 1.42V CL16-16-16-16-32-48 1T, tRFC:288, B-die
Video Card(s) Sapphire Nitro+ RX 7900XTX (Dec 2023) 314~465W (366W current) PowerLimit, 1060mV, Adrenalin v24.2.1
Storage Samsung NVMe: 980Pro 1TB(OS 2022), 970Pro 512GB(2019) / SATA-III: 850Pro 1TB(2015) 860Evo 1TB(2020)
Display(s) Dell Alienware AW3423DW 34" QD-OLED curved (1800R), 3440x1440 144Hz (max 175Hz) HDR1000
Case None... naked on desk
Audio Device(s) Astro A50 headset
Power Supply Corsair HX750i, 80+ Platinum, 93% (250~700W), modular, single/dual rail (switch)
Mouse Logitech MX Master (Gen1)
Keyboard Logitech G15 (Gen2) w/ LCDSirReal applet
Software Windows 11 Home 64bit (v23H2, OSB 22631.3155)
A 3900X will hit the 140A on heavy all core load. This is the first PBO limit the CPU finds, called EDC “Electrical Design Current”. Even with manual PBO settings and released EDC (you can set it to 1000A if you like) the CPU hardly will surpass it. And if it is, by a small margin. This is not allowed by the silicon controller. There is no way around that unless a static OC take place, and anything is possible. I don’t recommend...

Other PBO limits
PPT (Package Power Tracking =Total socket power draw)
TDC (Thermal Design Current)

TDC (90A) is irrelevant below temperature throttling threshold of 95C.

PPT for 3900X is 140W and it’s not easy to hit the value unless static OCed or in auto boosting under low temperatures. Around 70-75C will be around 135W. If you manage to cool it down, under 70C, EDC will also drop and will allow more clock and voltage and it may hit the 140W PPT limit.

If you uncap PPT with manual PBO settings (like 145W) it will pass 140W if EDC and temp is allow this.

If you cap EDC to 135A or 130A or even more then the PPT will almost certainly surpass the 140W (with more clock/voltage) as long as you give it headroom by setting it 145W or 150W. Again, temperature must allow this.

More or less this is the function of ZEN2 silicon FITness controller.
 
Top