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MSI PRO B840M-B Motherboard, mATX - Supports AMD Ryzen 9000/8000 / 7000 Processors, AM5 - DDR5 Memory Boost (8000+ MT/s OC), PCIe 4.0 x16, M.2 Gen4, 2.5G LAN9.6Our score 4 photos
MBrandmsiMmsi224 products in our catalogSee all msi products →ID DBD-17716

MSI PRO B840M-B Motherboard, mATX - Supports AMD Ryzen 9000/8000 / 7000 Processors, AM5 - DDR5 Memory Boost (8000+ MT/s OC), PCIe 4.0 x16, M.2 Gen4, 2.5G LAN

9.6/10 our score 4.4 (66 ratings on Amazon)

ULTRA POWER - SUPPORTS THE LATEST RYZEN 9000 PROCESSORS IN HIGH PERFORMANCE - The PRO B840M-B employs a Direct 7 Phase (P-PAK) VRM for the A

Processor SocketSocket AM5Memory Clock Speed8000Memory Storage Capacity128 GBRam Memory Maximum Size256 GBGraphics Card InterfacePCI Express 4.0Memory Slots Available2

About this item

  • ULTRA POWER - SUPPORTS THE LATEST RYZEN 9000 PROCESSORS IN HIGH PERFORMANCE - The PRO B840M-B employs a Direct 7 Phase (P-PAK) VRM for the AMD B840 chipset (AM5, Ryzen 9000 / 8000 / 7000) with MSI Core Boost technology for improved stability & performance
  • PASSIVE & AI COOLING - A chipset heatsinks provide passive cooling; Frozr AI cooling automatically adjusts system fan settings based on CPU & GPU temperatures
  • DDR5 MEMORY, PCIe 4.0 x16 SLOT - 2 x DDR5 DIMM slots enable extreme memory overclocking speeds (1DPC 1R, 8000+ MT/s OC); 1 x PCIe 4.0 x16 slot (64GB/s) with Steel Armor supports cutting-edge graphics cards
  • DOUBLE M.2 CONNECTORS - Storage options include 2 x M.2 Gen4 x4 64Gbps slots
Category: PC Parts › MotherboardsRanked #99 of 616 in PC Parts
9.6Our score
Our verdict

ULTRA POWER - SUPPORTS THE LATEST RYZEN 9000 PROCESSORS IN HIGH PERFORMANCE - The PRO B840M-B employs a Direct 7 Phase (P-PAK) VRM for the A

Ranked #99 in PC Parts · 4 things we like

Quick answer The MSI PRO B840M-B Motherboard scores 9.6/10 with us. Amazon owners rate it 4.4 out of 5 across 66 reviews, in line with the 4.3 average of the 147 motherboards we track. It was listed at $97.95 on Amazon when we last checked in September 2026. Key facts: processor socket Socket AM5, memory clock speed 8000, memory storage capacity 128 GB.

PRO B840M-B: Business Elegance Designed for efficient and stable performance on the AMD B840 chipset (Ryzen 9000 / 8000 / 7000 supported, AM5), the MSI PRO B840M-B motherboard includes premium GPU support with a PCIe 4.0 x16 slot, improved DDR5 memory support (8000+ MT/s OC), and extensive M.2 Gen4 storage options. To ensure stable power delivery to the latest Ryzen 9000 processors, the PRO B840M-B is equipped with a Direct 7 Phase (P-PAK) VRM for the CPU and a 8-pin CPU power connector, augmented with multiple passive cooling features. MSI B840 PRO motherboards feature durable PCBs with 2oz of thickened copper for improved signal clarity.

Connectivity includes Realtek 2.5G LAN, USB 5Gbps Type-A, 4K/60Hz display support, and 7.1 HD audio. For professionals looking for an efficient AMD Ryzen 9000 / 8000 / 7000 platform that unites PCIe 4.0 x16 graphics card architecture, improved DDR5 sup

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Product information

24 specifications
Processor SocketSocket AM5
Compatible DevicesPersonal Computer
RAM Memory TechnologyDDR5
Compatible ProcessorsSupports AMD Ryzen 9000/ 8000/ 7000 Series Desktop Processors
Chipset TypeAMD B840
Memory Clock Speed8000
PlatformWindows 11
CPU ModelAMD Ryzen 7
Memory Storage Capacity128 GB
Ram Memory Maximum Size256 GB
Main Power Connector Type24-Pin
Graphics Card InterfacePCI Express 4.0
Memory Slots Available2
Number of Ports12
Total Usb Ports1
Number of Ethernet Ports1
Total PCIe Ports1
Brandmsi
Model NameMSI PRO B840M-B Motherboard
Model NumberPRO B840M-B
Number of Items1
Item Weight2 pounds
Mfr Part NumberMSI PRO B840M-B
Warranty Description3 Year Manufacturer

Pros & cons

What we like
  • ULTRA POWER - SUPPORTS THE LATEST RYZEN 9000 PROCESSORS IN HIGH PERFORMANCE - The PRO B840M-B employs a Direct 7 Phase (P-PAK) VRM for the AMD B840 chipset (AM5, Ryzen 9000 / 8000 / 7000) with MSI Core Boost technology for improved stability & performance
  • PASSIVE & AI COOLING - A chipset heatsinks provide passive cooling; Frozr AI cooling automatically adjusts system fan settings based on CPU & GPU temperatures
  • DDR5 MEMORY, PCIe 4.0 x16 SLOT - 2 x DDR5 DIMM slots enable extreme memory overclocking speeds (1DPC 1R, 8000+ MT/s OC); 1 x PCIe 4.0 x16 slot (64GB/s) with Steel Armor supports cutting-edge graphics cards
  • DOUBLE M.2 CONNECTORS - Storage options include 2 x M.2 Gen4 x4 64Gbps slots
What could be better

    MSI PRO B840M-B Motherboard: questions & answers

    Is the MSI PRO B840M-B Motherboard worth buying?

    Yes, it is one of the stronger picks in its group. We score the MSI PRO B840M-B Motherboard 9.6 out of 10. Amazon owners rate it 4.4 out of 5 across 66 reviews, in line with the 4.3 average of the 147 motherboards we track.

    How much does the MSI PRO B840M-B Motherboard cost?

    It was listed at $97.95 on Amazon when we last checked in September 2026. That is cheaper than the $183.99 median for motherboards in our catalog. Amazon prices change daily, so use the price button on this page to see the current figure.

    What options does the MSI PRO B840M-B Motherboard come in?

    Amazon lists 5 options. Model: PROB850MAWIFI, MPG B850 Edge TI WiFi, B850 Gaming Plus WiFi PZ, MAGB850MMORTARWIFI, B850 GAMING PLUS WIFI V1. Pick an option on this page and the button opens exactly that model.

    What are the key specs of the MSI PRO B840M-B Motherboard?

    Processor Socket: Socket AM5; Memory Clock Speed: 8000; Memory Storage Capacity: 128 GB; Ram Memory Maximum Size: 256 GB; Graphics Card Interface: PCI Express 4.0; Memory Slots Available: 2. All 24 specifications are in the product information table on this page.

    What are good alternatives to the MSI PRO B840M-B Motherboard?

    Similar, well-rated motherboards in our catalog: MSI PRO B650-S WiFi V1 Motherboard (9.4/10, 4.7 stars from 111 owners); MSI B550M Gaming Plus WIFI6E Motherboard (9.2/10, 4.6 stars from 12 owners); MSI MPG X870I Edge TI EVO WiFi Motherboard (8.6/10, 4.5 stars from 443 owners).

    MSI PRO B650-S WiFi V1 MotherboardMSI B550M Gaming Plus WIFI6E MotherboardMSI MPG X870I Edge TI EVO WiFi Motherboard

    Customer reviews

    All reviews on Amazon
    4.466 global ratings
    5 star80%
    4 star10%
    3 star0%
    2 star10%
    1 star0%

    Breakdown from the 10 most helpful reviews we imported.

    L
    Luna
    Verified purchaseMarch 25, 2026
    Worth the Extra Money

    This is a really good motherboard with modern and plentiful rear ports, with 2 USB-C ports, 6 regular USB ports, wifi, 2.5 Gigabit Ethernet, Display Port, and HDMI. Had no issues with it while building my PC, and the tooless mechanism for the NVME made installing storage a breeze. Even though it does cost more than most Micro ATX boards, that's definitely worth it with how long it'll last me for the rest of the AM5 platforms life. A good long term value for money.

    J
    Joseph Clark
    Verified purchaseJuly 22, 2026
    Fantastic little motherboard

    Great little motherboard. The DDR5-6000 option appeared once I updated the BIOS, which was really easy, thank you MSI.I'm running an amped DIY Steam PC with Bazzite and things have worked flawlessly

    N
    Nate C
    Verified purchaseApril 20, 2026
    Great Value

    Perfect value motherboard in my opinion. It looks great, isn’t lacking in features, runs the 7800x3d great, which can’t be said for other brands on x3d CPUs.

    M
    Mick B
    Verified purchaseApril 5, 2026
    No visible wires, great back connect board

    Great looking and excellent performance from a great brand. Perfect board for my build.

    C
    Chris Mcculler
    Verified purchaseJuly 3, 2026
    It's ok

    Don't buy a motherborard just because it has built in wifi, the wifi modules doesn't seem all that great, board works fine otherwise

    A
    Alae Bouchlih
    Verified purchaseFebruary 23, 2026
    Gaming and Streaming go for it!

    Motherboard is goodQuality: 8/10Ports: Enough for most uses!Wifi: Good quality !! man Wifi 7 hahaBefore you turn on make sure to update biosSupport Gen 5after test what I could say performance worth price!

    P
    pH
    Verified purchaseJanuary 27, 2026
    Board arrived defective - trouble shooting takes time but is straightforward.

    Board was defective. Nice mATX design. Board would not post. CPU not detected (red LED) and DRAM not detected (yellow LED) remained lit, despite using two different AMD 5 CPUs and two different sets of DRAM. CMOS button worked, but FLASH BIOS did not. Returned for full refund. MSI usually very reliable. I'll probably buy another of teh same model.

    I
    Isaac Thibodeaux
    Verified purchaseAugust 20, 2026
    Brought me down to 20-40 ping and makes my new CPU purr 10/10

    Zero problems installing, and the SSD port is cool in my opinion, and as soon as I figured out the initial startup key bind it ran it's bios and booted up like nothing had even changed which I love, also my ping in games went from 80-130 on my old motherboard to 40-20 on this motherboard with the same Internet plan. Ryzen chip purrs with this thing and my Nvidia GPU fits no problem and works great along with my ram which I wasn't sure would work since it isn't mainstream.

    Customer reviews are shown as published on Amazon and are not written by Do Best Deal.