ASUS AMD PRIME B850M-A WIFI-CSM (AM5) mATX Motherboard, DDR5 256GB, 1x PCIe 5.0 x16, 3x M.2 slots, 4x SATA, Wi-Fi 6E, 2.5Gb LAN, 1x HDMI, 2x DP | PRIME B850M-A WIFI-CSM

ASUS AMD PRIME B850M-A WIFI CSM (AM5) mATX Motherboard

ASUS Prime series motherboards are expertly engineered to unleash the full potential of AMD Ryzen™ 9000 series processors. The PRIME B850M-A WIFI-CSM motherboard provides users and PC DIY builders with a range of performance optimizations via intuitive software and firmware features. It’s designed to be Advanced AI PC-ready, offering the power and connectivity needed for demanding AI applications.

SPECIFICATIONS
Model
PRIME B850M-A WIFI-CSM

News Updates
Socket AM5,

CPU
AMD Socket AM5 for AMD Ryzen™ 9000 8000 7000 Series Desktop Processors*
Supports up to AMD 170W CPU

Chipset
AMD B850 Chipset

Memory
4 x DIMM slots, max. 256GB, DDR5 Supports up to 8000+MT/s (OC) with Ryzen™ 9000 8000 7000 Series Processors, ECC and Non-ECC Un-buffered DIMM*
Dual channel memory architecture
Supports AMD Extended Profiles for Overclocking (EXPO™)
ASUS Enhanced Memory Profile (AEMP)

Graphics
2 x DisplayPort**
1 x HDMI™ port***

Expansion Slots
AMD Ryzen™ 9000 7000 Series Desktop Processors*
1 x PCIe 5.0 x16 slot (supports x16 mode)
AMD Ryzen™ 8000 Series Desktop Processors
1 x PCIe 4.0 x16 slot (supports x8/x4 mode)**
AMD B850 Chipset
1 x PCIe 4.0 x16 slot (supports x1 mode)

Storage
Supports 3 x M.2 slots and 4 x SATA 6Gb/s ports
AMD Ryzen™ 9000 7000 Series Desktop Processors
M.2_1 slot (Key M), type 2280 (supports PCIe 5.0 x4 mode)
M.2_2 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode)
AMD Ryzen™ 8000 Series Desktop Processors
M.2_1 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode)
M.2_2 slot (Key M), type 2280 (supports PCIe 4.0 x4/x2 mode)*
AMD B850 Chipset
M.2_3 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode)
4 x SATA 6Gb/s ports

Ethernet
1 x Realtek 2.5Gb Ethernet
ASUS LANGuard

Wireless Bluetooth
‘Wi-Fi 6E
2×2 Wi-Fi 6E (802.11ax)
Supports 2.4/5/6GHz frequency band*
Bluetooth® v5.3**

USB
Rear USB (Total 8 ports)
2 x USB 10Gbps ports (2 x Type-A )
2 x USB 5Gbps ports (2 x Type-A)
4 x USB 2.0 ports (4 x Type-A)
Front USB (Total 7 ports)
1 x USB 5Gbps connector (supports USB Type-C®)
1 x USB 5Gbps header supports 2 additional USB 5Gbps ports
2 x USB 2.0 headers support 4 additional USB 2.0 ports

Audio
Realtek 7.1 Surround Sound High Definition Audio CODEC*
– Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking
– Supports up to 24-Bit/192 kHz playback
Audio Features
– Audio Shielding
– Premium audio capacitors
– Dedicated audio PCB layers

BIOS
256 Mb Flash ROM, UEFI AMI BIOS

Manageability
WOL by PME, PXE

Operating System
Windows® 11, Windows® 10 64-bit

Form Factor
mATX Form Factor
9.6 inch x 9.6 inch (24.4 cm x 24.4 cm)

Product Last Updated: 08/11/2026

* Whilst we endevour to have the correct information on our products provided from the supplier/manufacturer errors do occur. If you would like to double check the information, please feel free to contact us and we will be more than happy to confirm information on the item prior to purchase. In the event that product information is incorrect due to information we received from our supplier or manufacturer, we do not take responsibility or be held liable for damage(s) or loss(s). We will work with you and do our best to make the best of a bad situation and work with our supplier(s) and/or manufacturer(s) to supply the correct information for the item purchased etc..