$261^.11

$265.11

Free 30-day Returns

Limit 99999 per customer.

Sold by Deal Targets

Hot Seller

4.5 (3,585 seller ratings)

Shipped by Deal Targets

Price alert

Add to Wish List

Best Sellers

OneDealOutlet Canada

4.3 (3,157 total ratings)

$276^.10
+ FREE SHIPPING

TECH EDGE

Hot Seller

4 (4 total ratings)

$499^.99
+ FREE SHIPPING

Zyngear

5 (1 total rating)

$899^.00
+ FREE SHIPPING

Meet Your Seller

Deal Targets

See Seller Store

More Resources

AM5 vs Intel LGA 1700 & LGA 1851 Platform Comparison

Choosing the Right Gaming Motherboard Guide

MSI MEG X870E Godlike X Edition Review

How to Install a CPU Safely

Main image of ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 2 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 3 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 4 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 5 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 6 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 7 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 8 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 9 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 10 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 11 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 12 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 13 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 14 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 15 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 16 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 17 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 18 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 19 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Alt view image 20 of 20 - ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Shop All ASUS Products | Visit Deal Targets Store

ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Be the first to review this product...

Option: PRIME B840M-A WIFI-CSM

ROG STRIX B850-F GAMING WIFI
ROG STRIX B850-A GAMING WIFI
ROG STRIX B850-I GAMING WIFI
TUF GAMING B850-PLUS WIFI
TUF GAMING B850M-PLUS WIFI
PRIME B840-PLUS WIFI
PRIME B840M-A WIFI-CSM
B850 MAX GAMING WIFI W
TUF GAMING B850M-E WIFI
PRIME B850-PLUS WIFI
TUF GAMING B850M-PLUS WIFI7
ROG Strix B850-F GAMING WIFI7 NEO

ASUS Corporate Stable Model (CSM) is a commercial program designed to provide stable and reliable motherboards.
Ready for Advanced AI PC: Designed for the future of AI computing, with the power and connectivity needed for demanding AI applications
AMD AM5 Socket: Ready for AMD Socket AM5 for AMD Ryzen 9000 & 8000 & 7000 Series Desktop Processors
Enhanced Power Solution: 6-layer PCB, alloy chokes and durable capacitors for stable power delivery
Ultrafast Connectivity: Wi-Fi 6E, PCIe 4.0 x16 slot, PCIe 4.0 M.2 slots, Realtek 2.5Gb Ethernet, rear USB 10Gbps Type-A ports, rear and front USB 5Gbps Type-C support
Comprehensive Cooling: VRM and M.2 heatsinks, PCH heatsink, hybrid fan headers and Fan Xpert 2+
DIY Friendly Design: Pre-mounted I/O shield, BIOS FlashBack, M.2 heatsink, Q-Antenna, Q-Dashboard, Q-LED Core
Unmatched Personalization: Three Addressable Gen 2 headers, all configurable with ASUS-exclusive Aura Sync RGB lighting

Overview

Specs

Reviews

Asus Prime B840M-A WIFI-CSM Gaming Desktop Motherboard - AMD B840 Chipset - Socket AM5 - Micro ATX - Ryzen 7, Ryzen 8, Ryzen 9 Processor Supported - 192 GB DDR5 SDRAM Maximum RAM - DIMM, UDIMM - 4 x Memory Slots - Gigabit Ethernet - 2.5G igabit Ethernet - IEEE 802.11 ax - HDMI - DisplayPort - 4 x SATA Interfaces

Model
Brand	ASUS
Model	PRIME B840M-A WIFI-CSM
Part Number	90MB1J20-MVAAYC

Supported CPU
CPU Socket Type	AM5
CPU Type	Ryzen 7000 Series / Ryzen 8000 Series / Ryzen 9000 Series

Chipsets
Chipset	AMD B840

Memory
Number of Memory Slots	4x288pin (DDR5)
Memory Standard	Up to 7600+MT/s (OC)
Maximum Memory Supported	192GB
Channel Supported	Dual Channel
ECC Supported	Yes
Buffer Supported	Un-buffered
Memory Feature	Dual channel memory architecture Supports AMD Extended Profiles for Overclocking (EXPO) ASUS Enhanced Memory Profile (AEMP)

Expansion Slots
PCI Express 4.0 x16	AMD Ryzen 9000 & 7000 Series Desktop Processors* 1 x PCIe 4.0 x16 slot (supports x16 mode) AMD Ryzen 8000 Series Desktop Processors 1 x PCIe 4.0 x16 slot (supports x8/x4 mode)
PCI Express 3.0 x16	AMD B840 Chipset 2 x PCIe 3.0 x16 slots (support x1 mode)

Storage Devices
Serial ATA (SATA)	4 x SATA 6Gb/s
M.2	AMD Ryzen 9000 & 8000 & 7000 Series Desktop Processors M.2_1 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode) M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode) AMD B840 Chipset M.2_3 slot (Key M), type 2280 (supports PCIe 3.0 x4 mode)
SATA RAID	AMD RAIDXpert2 Technology supports both PCIe RAID 0/1/5/10 and SATA RAID 0/1/5/10. *RAID 5 Function is only supported by AMD Ryzen 9000 series CPU.

Onboard Audio
Audio Channels	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 * A chassis with an HD audio module in the front panel is required to support 7.1 Surround Sound audio output.

Onboard LAN
Max LAN Speed	2.5Gbps
Wireless LAN	Wi-Fi 802.11 ax
Bluetooth	Bluetooth 5.3

Rear Panel Ports
Back I/O Ports	2 x USB 10Gbps ports (2 x Type-A) 1 x USB 5Gbps port (1 x USB Type-C) 4 x USB 2.0 ports (4 x Type-A) 2 x DisplayPort 1 x HDMI port 1 x Wi-Fi module 1 x Realtek 2.5Gb Ethernet port 3 x Audio jacks 1 x BIOS FlashBack button

Internal I/O Connectors
Onboard USB	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
Other Connectors	Fan and Cooling Related 1 x 4-pin CPU Fan header 1 x 4-pin CPU OPT Fan header 1 x 4-pin AIO Pump header 3 x 4-pin Chassis Fan headers Miscellaneous 3 x Addressable Gen 2 headers 1 x Clear CMOS header 1 x COM Port header 1 x Front Panel Audio header (F_AUDIO) 1 x S/PDIF Out header 1 x SPI TPM header (14-1 pin) 1 x 10-1 pin Front System Panel header

Physical Spec
Form Factor	Micro ATX
Dimensions (W x L)	9.6" x 9.6"
Power Pin	1 x 24-pin Main Power connector 1 x 8-pin +12V CPU Power connector

Software Feature
BIOS Feature	256 Mb Flash ROM, UEFI AMI BIOS
Software	ASUS Exclusive Software Armoury Crate - Aura Creator - Aura Sync - Fan Xpert 2+ - Power Saving ASUS DriverHub ASUS GlideX TurboV Core ASUS CPU-Z Norton 360 Deluxe (60 Days Free Trial) WinRAR (40 Days Free Trial) UEFI BIOS ASUS EZ DIY - ASUS CrashFree BIOS 3 - ASUS EZ Flash 3 - ASUS UEFI BIOS EZ Mode - ASUS MyHotkey
Windows 11	Windows 11, Windows 10 64-bit

Features
Features	ASUS 5X PROTECTION III - DIGI+ VRM - LANGuard - Overvoltage protection - SafeSlot Core+ - Stainless-steel back I/O ASUS Q-Design - Q-Antenna - Q-Dashboard - Q-DIMM - Q-LED Core - Q-Slot ASUS Thermal Solution - M.2 heatsink - VRM heatsink design ASUS EZ DIY - BIOS FlashBack button - BIOS FlashBack LED - Pre-mounted I/O shield Aura Sync - Addressable Gen 2 headers

Packaging
Package Contents	Cables 2 x SATA 6Gb/s cables Miscellaneous 1 x ASUS WiFi Q-Antenna 1 x M.2 rubber package 3 x Screw packages for M.2 SSD Documentation 1 x Quick start guide

Additional Information
First Listed on Newegg	October 16, 2025

Warranty & Returns

Warranty, Returns, And Additional Information

Warranty

Please contact the Seller directly for warranty information. Warranty information may also be found on the Manufacturer's website.
Read full details
CONTACT

Return Policies

Return for refund within: 30 days
Return for replacement within: 30 days
This item is covered by Deal Targets Return Policy

Manufacturer Contact Info

For a directory of all our manufacturers, please click below.
Manufacturers Directory

Best Sellers

Meet Your Seller

ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Learn more about the ASUS PRIME B840M-A WIFI-CSM

Customer Reviews of the ASUS PRIME B840M-A WIFI-CSM

Warranty & Returns

Warranty, Returns, And Additional Information

Warranty

Return Policies

Manufacturer Contact Info

Item#: 9SIADGEKM99858

Best Sellers

Meet Your Seller

ASUS PRIME B840M-A WIFI-CSM AMD AM5 B840 mATX motherboard, Advanced AI Ready, DDR5, PCIe 4.0 Ready, three M.2 slots, Wi-Fi 6E, 2.5Gb LAN, DisplayPort, HDMI, USB 5Gbps Type-C, BIOS FlashBack, Aura

Learn more about the ASUS PRIME B840M-A WIFI-CSM

Customer Reviews of the ASUS PRIME B840M-A WIFI-CSM

Warranty & Returns

Warranty, Returns, And Additional Information

Warranty

Return Policies

Manufacturer Contact Info