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MSI PRO B840M-B
MSI · Motherboard

MSI PRO B840M-B

B840 · AM5 · mATX · DDR5

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  • Chipset B840
  • Form factor mATX
  • Memory slots 2
  • Max memory 128 GB
  • Socket AM5
  • Memory type DDR5

MSI PRO B840M-B is a mATX and B840 chipset motherboard for AM5 processors and DDR5 memory. It came out in 2025.

Released
2025-05-31
Socket
AM5

Specifications

Key specs

Chipset
B840
Form factor
mATX
Memory slots
2
Max memory
128 GB
Socket
AM5
Memory type
DDR5
Released
2025-05-31
Part number
PRO B840M-B
EAN / UPC
4711377360166

Processor

Processor manufacturer
AMD
Processor socket
Socket AM5
Compatible processor series
AMD Ryzen 7000 Series, AMD Ryzen 8000 Series, AMD Ryzen 9000 Series
Supported processor sockets
Socket AM5

Memory

Supported memory types
DDR5-SDRAM
Number of memory slots
2
Memory slots type
DIMM
Memory channels
Dual-channel
ECC сompatibility
Non-ECC
Supported memory clock speeds
4800,5600,8000 MHz
Supported memory clock speed (max)
8000 MHz
Maximum internal memory
128 GB
View all specifications +8 more sectionsShow fewer specifications

Storage controllers

Supported storage drive types
HDD & SSD
Supported storage drive interfaces
M.2, Micro SATA III
Number of HDDs supported
4
Number of storage drives supported
6
RAID support
Yes
RAID levels
0, 1, 10

Internal I/O

USB 2.0 connectors
4
USB 3.2 Gen 1 (3.1 Gen 1) connectors
2
USB 3.2 Gen 2 (3.1 Gen 2) connectors
1
Number of SATA III connectors
4
Total number of SATA connectors
4
Number of CPU fan connectors
1
Number of chassis fan connectors
5
Number of water pump connectors
1
RGB LED pin header
Yes
Number of RGB LED pin headers
3

Rear panel I/O ports

USB 2.0 ports quantity
2
USB 3.2 Gen 1 (3.1 Gen 1) Type-A ports quantity
4
Ethernet LAN (RJ-45) ports
1
HDMI ports quantity
1
HDMI version
2.1

Network

Ethernet LAN
Yes
Ethernet interface type
2.5 Gigabit Ethernet
LAN controller
Realtek RTL8125D
Top Wi-Fi standard
Not available

Features

Motherboard chipset
AMD B840
Audio chip
Realtek ALC897
Audio output channels
7.1 channels
Product colour
Black
Component for
PC
Motherboard form factor
micro ATX
Motherboard chipset family
AMD
Windows operating systems supported
Windows 11 x64

Expansion slots

PCI Express x16 slots
2
PCI Express x16 (Gen 4.x) slots
1
Number of M.2 (M) slots
2
1st M.2 largest key size
2280
1st M.2 highest PCI Express generation
4.0
2nd M.2 largest key size
2280
2nd M.2 highest PCI Express generation
4.0

BIOS

BIOS type
UEFI AMI
BIOS memory size
256 Mbit
ACPI version
6.5
System Management BIOS (SMBIOS) version
3.7

Weight & dimensions

Width
226 mm
Depth
243.8 mm

Check the manufacturer's page before buying.

Ready to buy? Get the MSI PRO B840M-B at today's price.Buy now on Amazon

Compatible processors

AM5 socket

Compatible memory

DDR5

About this product

BUSINESS ELEGANCE

The PRO Series is tailored to professionals from all walks of life. The lineup features impressive performance and high quality, while aiming to provide users incredible experience. Users who care about productivity and efficiency can definitely count on the MSI PRO Series to assist you with multitasking and increasing efficiency. MSI motherboards are designed with advanced hardware and technology, well-supporting the demanding computing usage of gaming and AI. Moreover, we also introduce AI to MSI Center and BIOS, making everything more effortless than before.

DIRECT 7+2+1 POWER DESIGN

Unleash and sustain the maximum performance with a VRM design built with a total of 7+2+1 digital power phases. With an 8-pin power connector, PRO B840M-B is ready for the challenge of heavy-loading tasks. Chipset Heatsink The chipset heatsink is designed to reduce dust and noise and capable of maintaining high efficiency of heat dissipation.

HIGH-BANDWIDTH AND LOW-LATENCY NETWORK

MSI’s premium network solution provides incredible data transfer speed for demanding users.

Datasheet (PDF)

PRO B840M-B vs similar motherboards

MSI PRO B840M-BMSI B840M GAMING WIFI6EASUS PRIME B840M-RASUS PRIME B840M-K
ChipsetB840B840B840B840
Form factormATXmATXmATXmATX
Memory slots2222
Max memory128 GB128 GB128 GB128 GB
SocketAM5AM5AM5AM5
Memory typeDDR5DDR5DDR5DDR5
Released2025202520262026

Questions about the PRO B840M-B

What are the main specs of the MSI PRO B840M-B?

B840, AM5, mATX, DDR5, 2 RAM slots.

Which chipset does the MSI PRO B840M-B use?

B840.

What form factor is the MSI PRO B840M-B?

mATX.

Which socket does the MSI PRO B840M-B use?

AM5.

When did the MSI PRO B840M-B come out?

It was released in 2025/05 (MSI).

With photos

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