Motherboards

MSI PRO B850M-B GEN4

Supports AMD Ryzen™ 9000 / 8000 / 7000 Series Desktop Processors
Supports DDR5 Memory, Dual Channel DDR5 8200+ MT/s (OC)
Ultra Performance: Direct 7+2+1 Power System with P-PAK, an 8-pin CPU power connector, Core Boost, Memory Boost, 6-layer PCB made by 2oz thickened copper and server-grade level material
EZ DIY: EZ M.2 Clip II and EZ PCIe Clip II
Lightning Fast Game experience: PCIe 5.0 slot and Lightning Gen 5 x4 M.2
5G LAN: the latest solution for professional and multimedia use, delivering secure, stable, and high-speed networking and data transmission

Category: Motherboards Brand: MSI

Sales Enquiry

Specification	Details
Chipset	AMD B850
CPU	Supports AMD Ryzen™ 9000/ 8000/ 7000 Series Desktop Processors Socket AM5
Memory
Configuration	2x DDR5 UDIMM, Maximum Memory Capacity 128GB
Memory Support	DDR5 8200 – 5600 (OC) MT/s / 5600 – 4800 (JEDEC) MT/s
Ryzen™ 9000 Series Processors max. overclocking frequency	– 1DPC 1R Max speed up to 8200+ MT/s – 1DPC 2R Max speed up to 8000+ MT/s
Features	Supports AMD POR Speed and JEDEC Speed Supports Memory Overclocking and AMD EXPOTM Supports Dual-Channel mode Supports Non-ECC, Un-buffered memory Supports CUDIMM, Clock Driver bypass mode only*
Note	– The DIMM slots on this motherboard only have single-sided latches. – Memory compatibility and supported speeds can vary depending on the CPU and memory configuration. For detailed information, please refer to the Memory Compatibility List available on the product’s Support page or visit https://www.msi.com/support/. * CUDIMM support and POR boot frequency may vary by CPU series, with manual overclocking available after boot. Certain CPUs may fail to boot, but future BIOS updates will improve compatibility.
Onboard Graphics
Ports	1x HDMI™ Support HDMITM 2.1, maximum resolution of 4K 60Hz* 1x DisplayPort Support DisplayPort 1.4, maximum resolution of 4K 60Hz* *Available only on processors featuring integrated graphics. Graphics specifications may vary depending on the CPU installed.
Slot
Configuration	1x PCI-E x16 slot 1x PCI-E x1 slot PCI_E1 Gen PCIe 3.0 supports up to x1 (From Chipset) PCI_E2 Gen PCIe 4.0 supports up to x16 (From CPU)
PCI_E2 slot	– Supports PCIe 4.0 x16 (For Ryzen™ 9000/ 7000 Series processors) – Supports PCIe 4.0 x8 (For Ryzen™ 8700/ 8600/ 8400 Series processors) – Supports PCIe 4.0 x4 (For Ryzen™ 8500/ 8300 Series processor)
Audio
Configuration	Realtek® ALC897 Codec 7.1-Channel High Definition Audio
Storage
Configuration	2x M.2 M.2_1 Source (From CPU) supports up to PCIe 5.0 x4 , supports 2280 devices M.2_2 Source (From CPU) supports up to PCIe 4.0 x4 , supports 2280 devices 4x SATA 6G
M2_1 slot	– Supports up to PCIe 5.0 x4 (For Ryzen™ 9000/ 7000 Series processors) – Supports up to PCIe 4.0 x4 (For Ryzen™ 8000 Series processors)
M2_2 slot	– Supports up to PCIe 4.0 x4 (For Ryzen™ 9000/ 8700/ 8600/ 8400/ 7000 Series processors) – Supports up to PCIe 4.0 x2 (For Ryzen™ 8500/ 8300 Series processors)
RAID
Support	Supports RAID 0 and RAID 1 for M.2 NVMe storage devices Supports RAID 0, RAID 1, and RAID 10 for SATA storage devices
USB
Configuration	2x USB 2.0 (Rear) 4x USB 2.0 (Front) 3x USB 5Gbps Type A (Rear) 1x USB 5Gbps Type C (Rear) 2x USB 5Gbps Type A (Front) 1x USB 10Gbps Type C (Front)
LAN
Ports	Realtek® 8125 2.5G LAN
Internal IO
Connectors	1x Power Connector(ATX_PWR) 1x Power Connector(CPU_PWR) 1x CPU Fan 1x Combo Fan (Pump_Sys Fan) 3x System Fan 2x Front Panel (JFP) 1x Chassis Intrusion (JCI) 1x Front Audio (JAUD) 1x Tuning Controller connector(JDASH) 3x Addressable V2 RGB LED connector (JARGB_V2) 1x RGB LED connector(JRGB) 1x TPM pin header(Support TPM 2.0) 4x USB 2.0 ports 2x USB 5Gbps Type A ports 1x USB 10Gbps Type C ports
WIRELESS LAN & BLUETOOTH
Chipset	Wi-Fi 7 Solution
Installation	The Wireless module is pre-installed in the M.2 (Key-E) slot
Performance	Supports MU-MIMO TX/RX, 2.4GHz/ 5GHz/ 6GHz* (320MHz) up to 5.8Gbps Supports 802.11 a/ b/ g/ n/ ac/ ax/ be Supports Bluetooth® 5.4**, MLO, 4KQAM
Notes	* 6GHz band support may depend on every country’s regulations and Wi-Fi 7 will be ready in Windows 11 version 24H2. ** The Bluetooth version may be updated, please refer to the Wi-Fi chipset vendor’s website for details. Bluetooth 5.4 will be ready in Windows 11 version 24H2.
LED FEATURE
Indicators	4x EZ Debug LED 1x EZ Memory Detection LED
Back Panel Ports
Configuration	DisplayPort HDMI™ Clear CMOS Button USB 5Gbps Type-A USB 5Gbps Type-A 2.5G LAN Audio connectors Flash BIOS Button USB 5Gbps Type-C USB 2.0
Operating System
Support	Support for Windows® 11 64-bit
Box Content
INCLUDES
PCB INFO
	mATX 226mmx243.84mm

Overview

MSI PRO B850M-B GEN4 – Compact Design, Modern Connectivity

The MSI PRO B850M-B GEN4 is a Micro-ATX motherboard built for users who want a high-quality AM5-based platform in a smaller, versatile form factor. Powered by the AMD B850 chipset, it supports AMD Ryzen™ 9000 / 8000 / 7000 Series desktop processors on the AM5 socket, offering excellent compatibility and future roadmap support.

Performance & Expansion
With dual DDR5 DIMM slots supporting up to 128 GB (OC), this board offers a solid memory foundation while fitting compact builds. It features one PCIe 4.0 x16 slot for a dedicated graphics card, and also supports modern storage with one M.2 Gen5 x4 slot (up to 128 Gb/s) plus one M.2 Gen4 x4 slot (up to 64 Gb/s) in addition to four SATA 6 Gb/s ports.

Connectivity & Networking
The board includes a 2.5G LAN interface for high-speed wired networking, supporting modern workflow demands. USB connectivity is robust with one USB 10 Gbps Type-C, six USB 5 Gbps ports, and six USB 2.0 ports, giving ample external device support.

Thermal & Practical Features
MSI’s build quality is evident with features like the extended heatsink design, pre-installed I/O shield for easier installation, and M.2 Shield FROZR for protecting high-performance NVMe SSDs from thermal throttling.

Design & Use Case
Designed for smaller builds or budget-conscious creators who still want modern performance, the PRO B850M-B GEN4 offers the essentials of the AM5 platform in a compact and efficient package. With its clean layout, reliable connectivity, and future-ready support, it’s ideal for micro-ATX systems, home studios, or business desktops that need high functionality without excess form factor.

Key Features:

Supports AMD Ryzen™ 9000 / 8000 / 7000 Series Desktop Processors
Supports DDR5 Memory, Dual Channel DDR5 8200+ MT/s (OC)
Ultra Performance: Direct 7+2+1 Power System with P-PAK, an 8-pin CPU power connector, Core Boost, Memory Boost, 6-layer PCB made by 2oz thickened copper and server-grade level material
Frozr Guard: Extended Heatsink, MOSFET thermal pads rated for 7W/mK, additional choke thermal pads and M.2 Shield Frozr are built for high performance system and non-stop experience
EZ DIY: EZ M.2 Clip II and EZ PCIe Clip II
Lightning Fast Game experience: PCIe 5.0 slot and Lightning Gen 5 x4 M.2
5G LAN: the latest solution for professional and multimedia use, delivering secure, stable, and high-speed networking and data transmission
Audio Boost: Reward your ears with studio grade sound quality for the most immersive gaming experience