ASUS Prime B840M-A WiFi CSM Motherboard

The ASUS Prime B840M-A WiFi CSM Motherboard supports AMD Ryzen 9000, 8000 and 7000 Series processors with an AM5 socket, featuring up to 4 x DDR5 memory, PCI-E 4.0 and 3.0 compatible expansion slots, 3 x M.2 slots, 4 x SATA ports (6Gb/s), 7 x rear USB ports, 4 x front panel USB header ports, 1 x Realtek 2.5Gb LAN, WiFi 6E, Bluetooth 5.3, Realtek 7.1 HD audio codec and an mATX form factor.

Warning: This product contains a button battery - If swallowed, a lithium battery can cause severe or fatal injuries with 2 hours. - Keep batteries out of reach of children. - If you think batteries may have been swallowed or placed inside any of the body, seek immediate medical attention.

Features

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Prime B840M-A WIFI-CSM

ASUS Prime series motherboards are expertly engineered to unleash the full potential of AMD Ryzen^™ 9000 series processors. The PRIME B840M-A WIFI-CSM motherboard provides users and PC DIY builders with a range of performance optimisations 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.

Performance

• AM5 Socket for AMD Ryzen™ Desktop processors
• 1 x PCIe 4.0 x 16
  (supports x 16 mode)
  SafeSlot Core+
• 2 x PCIe 3.0 x 16
  (support x1 mode)
• 8+2+1 phase digital power design
• 4 x DIMM slots
  DDR5 support
  Dual channel
  AEMP
• M.2_1 2280
  (PCIe 4.0 x 4 mode)
• M.2_2 2242/2260/2280
  (PCIe 4.0 x 4 mode)
• M.2_3 2280
  (PCIe 3.0 x 4 mode)(On the back of the motherboard.)

Cooling

• VRM heatsink
• Chassis fan header
• CPU OPT fan header
• CPU fan header
• AIO pump fan header
• Chipset heatsink
• 2 x Chassis fan headers

Flexibility

• 4 x USB 2.0 Type-A
• 2 x DisplayPort
• HDMI™ port
• BIOS FlashBack™ button
• 1 x USB 5Gbps
  Type-C®
• 2.5Gb Ethernet
• 2 x USB 10Gbps Type-A
• WiFi 6E
• 3 x Audio jacks
• 1 x USB 5Gbps header
  (supports 2 additional USB 5Gbps ports)
• 1 x USB 5Gbps connector
  (supports USB Type-C®)
• 2 x USB 2.0 headers
  (support 4 additional USB 2.0 ports)
• 4 x SATA 6Gbps ports

Customisation

• 2 x Addressable gen 2 headers
• 1 x Addressable gen 2 header

ASUS Corporate Stable Model

ASUS Corporate Stable Model (CSM) is a commercial Programme designed to provide stable and reliable motherboards. Offering up to 36-month product lifecycle support and 6-month end-of-life notice to allow sufficient lead times for your organisation to get ready for product transitions. Each purchase of an ASUS CSM motherboard comes with ASUS Control Center Express - server-grade IT management software.

* Lifecycle support, Programme offering and supply status may vary by region. Please consult your local sales representative for more information.

ASUS Control Center Express

ASUS Control Center Express is an integrated IT monitoring and management software designed to deploy faster, simplify IT operations and improve productivity with comprehensive control and user-friendly functions. ASUS Control Center Express is compatible with over 100 ASUS motherboards to provide a high-quality, TCO-optimised solution for your business needs.

Optimise IT Endpoint Management

Designed to assist IT staff in monitoring and controlling devices within their corporate networks, and facilitate inventory checking in multiple locations remotely.

Automate IT Maintenance

Allows IT staff to schedule automatic updates of the latest BIOS, software and utilities to specific or all devices at off-peak times, enhancing system stability and IT operational flexibility.

Securely Manage All of Endpoints

Securely manage endpoint configuration, portable storage access and PC software applications by enabling them to create grouping rules on individual devices.

Performance

AI Solutions

ASUS AI Solutions include AI Advisor as your technical expert with expertise in PC performance.

AI Advisor

ASUS AI Advisor allows users to explore the functionality and advanced features of ASUS motherboards in a simple and straightforward way. (Availability of ASUS AI Advisor may vary by region. AI Advisor functions may vary by platform.)

ASUS AI Advisor is an ASUS technical expert that's always available to answer your questions. Owners of compatible ASUS motherboards can interact with this AI-powered technology using natural language to learn more about their hardware. For DIY beginners, it can provide easy-to-understand explanations of one-click optimisation features like fan speed tuning, and for seasoned PC-building veterans, it can offer guidance and instructions on the latest features offered by ASUS. (Availability of ASUS AI Advisor may vary by region. AI Advisor functions may vary by platform.)

Digital Power Design

PRIME B840M-A WIFI-CSM features an 8+2+1 phase power design with discrete MOSFETs, ensuring efficient and stable power delivery for AMD processors plus steady performance for day-to-day use. (Image(s) for reference only)

• 8 - VCORE power
• 2 - SOC power
• 1 - Misc power

Six-Layer PCB Design

Enhanced Stability and Overclocking

The multi-layered printed circuit board design quickly dissipates heat around the voltage regulators to improve overall system stability and provide the CPU with more overclocking headroom.

Power Saving

Optimise Power with CPU, Lighting, and Fan Settings

The Power Saving function contains several settings to easily optimise power consumption and maximise energy savings. You can enable a CPU power limit, darken Aura lighting and set the fan profile to a Power Saving mode. You can also toggle the Power Saver plan that is built into Microsoft Windows.

Digi+ VRM Control

Real-Time Voltage Control

The Digi+ voltage-regulator module (VRM) delivers real-time control over voltage droop, automatically switching frequency and power-efficiency settings.

Enhanced Memory & Storage Performance

Enhanced DDR5 Performance

Comprehensive memory tuning options are the cornerstone of PRIME motherboards. The PRIME B840M-A WIFI-CSM maximises the potential of your DDR5 modules, from entry-level to extreme-speed kits. (Memory overclocking may vary between CPU series. Please refer to the spec table for detailed information.)

For entry-level modules without EXPO^™ support, ASUS Enhanced Memory Profile (AEMP) automatically detects memory chips and provides optimised profiles for enhanced performance.

For those looking to surpass stock DDR5 speeds, the PRIME B840M-A WIFI-CSM offers extensive AMD Extended Profiles for Overclocking (EXPO^™) support and a wide array of UEFI settings for further performance tweaks. (Supported memory types, data rates (speed), and number of DRAM modules vary depending on the CPU and memory configuration. For more information, please refer to the CPU/Memory Support List under the Support tab on the product information page or visit https://www.asus.com/support/download-center/.)

Three M.2 slots (up to 64 Gbps)

PRIME B840M-A WIFI-CSM offers a total of three M.2 slots, including two that support data-transfer speeds of up to 64 Gbps via PCIe 4.0, and one that supports PCIe 3.0. This enables quicker boot-up and app load times with OS or application drives. (Actual transmission speeds will be lower than the theoretical maximum speed.)

Cooling

Cooler by Design

The PRIME B840M-A WIFI-CSM motherboard is engineered with multiple onboard heatsinks and an array of hybrid fan headers to help ensure your rig stays cool and stable under intense workloads.

VRM Heatsinks and Thermal Pads

Massive VRM heatsink and essential thermal pads improve heat transfer from the MOSFETs and chokes for better cooling performance.

AIO Pump Header

Multiple Temperature Sources

Each header can dynamically reference three thermal sensors. Fan Xpert 2+ lets you to map the temperature of supported ASUS graphics cards to optimise cooling for GPU- and CPU-intensive tasks.

4-Pin PWM/DC Fan

Each onboard header supports auto-detection of PWM or DC fans.

M.2 Heatsink

Passive Chipset Heatsink

An aluminium passive chipset heatsink ensures optimal cooling and stable performance. It is more durable and longer-lasting than heatsinks with fans, which can be vulnerable to the buildup of dust and debris.

Smart Protection

A dedicated integrated circuit protects each fan header from overheating and excess current.

Smart Cooling Precision

ASUS Fan Xpert 2+

ASUS Fan Xpert 2+ software provides comprehensive control over fans. An Auto-Tuning mode intelligently configures all parameters with a single click. There’s also an Extreme Quiet mode that reduces chassis fan speeds to below the default minimum to keep your system whisper-quiet when performing light tasks. Fans can also be controlled via the UEFI BIOS.

Cooler Compatibility

ASUS AIO coolers offer robust performance, high overclocking potential, bold aesthetics and Customisable functionality for new motherboards, empowering you to build your dream gaming rig.

Flexibility

Empowering Connections

This motherboard offers a versatile range of connectivity, including support for WiFi 6E, PCIe 4.0 slot and an arsenal of USB ports which includes Type-C^® connections.

• WiFi 6E
• 2.5Gb Ethernet
• PCIe 4.0 M.2
• PCIe 4.0 slot
• USB 5Gbps

WiFi 6E

Built-in WiFi 6E (WiFi 6E availability and features are dependent on regulatory limitations and co-existence with 5 GHz WiFi) technology takes advantage of the newly available radio spectrum in the 6 GHz band. With triple the bandwidth of the 2.4/5/6 GHz band, WiFi 6E delivers ultrafast wireless networking speeds with improved capacity and better performance in dense wireless environments.

Realtek 2.5Gb Ethernet

Realtek 2.5 Gb Ethernet reduces CPU overhead and offers exceptionally high TCP and UDP throughput for faster, smoother data transfers.

Front USB 5Gbps Type-C^®

This motherboard features a USB 5Gbps Type-C^® front panel connector for speedy data transfers of up to 5Gbps.(Image(s) for reference only.)

Customisation

Personalisation

The PRIME B840M-A WIFI-CSM enhances the user experience across the board, from simplifying BIOS setting adjustments to offering Customisable RGB lighting controls for a uniquely personal system aesthetic.

UEFI BIOS

The UEFI interface delivers easy-to-use configuration options for PC beginners, and advanced features for veterans.

The renowned ASUS UEFI BIOS provides everything you need to configure, tweak and tune your system. It offers intelligently simplified options for PC DIY beginners, as well as comprehensive features for seasoned veterans.

BIOS Q-Dashboard

Simplify your motherboard configuration with BIOS Q-Dashboard. Its intuitive visual representation of hardware connections and corresponding BIOS settings takes the complexity out of setting up your system. Upgrade now, and discover the power of BIOS Q-Dashboard to easily and efficiently enhance your computing setup.

Advanced Mode

An intuitive Advanced mode offered via the UEFI lets you take complete control. A built-in search feature makes it easy to find options, and various advanced functions let you intelligently make nuanced adjustments so you can dial in performance just the way you want.

ASUS MyHotkey

This feature is flexible to Customise BIOS hotkey for various use scenarios, users can set F3 and F4 optional functions, and then during the Power-On Self-Test (POST) you can more efficiently toggle ASUS EZ Flash 3 or boot from a specified device.

Search Function

Quickly and easily find the option or setting you need.

ASUS User Profile

Easily port configuration settings between different BIOS versions or share them with friends.

EZ Mode

EZ mode displays vital settings and stats and also offers guided wizards, drag-and-drop functionality and one-click application of important settings — all to help you get your rig up and running in no time.

Intuitive Graphical Fan Control

Fine-tune individual fan settings simply by dragging a curve with the mouse.

Aura On/Off Mode (Stealth)

Easily enable or disable Aura RGB lighting or every onboard LED, for a subdued aesthetic touch.

ASUS GlideX

Enable seamless screen sharing and control across PCs, tablets, and smartphones via wired or wireless connections, supporting multiple platforms.

ASUS GlideX is a cross-device, cross-platform screen-sharing, screen-control and operation solution for enhanced productivity across PCs, tablets, and smartphones via wired or wireless connections. Features include screen mirroring, screen extension, unified control with one keyboard and mouse, easy file transfers, and using mobile cameras as PC webcams. It's compatible with Windows, macOS, Android, and iOS.

ASUS DriverHub

Simplify driver management with automatic detection, one-click installation and update for smooth, efficient system performance.

ASUS DriverHub streamlines the installation and management of ASUS drivers and utilities to keep your hardware up-to-date and performing optimally. This standalone application automatically detects current driver versions and presents available updates in a list view. By default, it supports ASUS motherboards, and users are invited to install ASUS DriverHub after OS installation. Additionally, ASUS DriverHub offers one-click installation and update checks, making it easier for users to keep their systems running smoothly and efficiently.

Armoury Crate

Customise Aura Sync RGB and control ASUS devices. Includes product registration and updates.

Within a single intuitive interface, Armoury Crate offers easily Customised Aura Sync RGB settings for every compatible device in your arsenal, plus controls for an ever-growing family of ASUS products, including keyboard and mouse preferences. Armoury Crate also integrates product registration and a news feed so that the ASUS community always has access to interesting updates.

• Dashboard
• Aura Sync
• Fan Xpert 2+
• Power Saving
• Driver & Manual Download
• Account Management

Aura Sync

Complete RGB lighting control for enthusiast systems, ensuring seamless synchronisation with compatible hardware.

Aura Sync Outshine the Competition

A well-tuned enthusiast system deserves a matching aesthetic. ASUS Aura offers full RGB lighting control with a variety of functional presets for the built-in RGB LEDs as well as strips and devices connected to the onboard RGB headers — and it can all be synced with an ever-growing portfolio of Aura-capable hardware.

• Static
• Breathing
• Strobing
• Rainbow
• Colour Cycle
• Starry Night
• Music Effect
• Smart
• Dark
• Adaptive Colour

Addressable Gen2 RGB Headers

Three addressable Gen 2 headers detect LED counts on compatible RGB devices, automatically adjusting lighting effects accordingly.

Customisation

DIY Friendly

The PRIME B840M-A WIFI-CSM motherboard features EZ PC DIY innovations that simplify and speed up the PC building process, making DIY easy and convenient.

Q-Antenna

With Q-Antenna, attaching a WiFi antenna to your PC is now easy and fast. Instead of slowly rotating two fasteners until they finally lock in, they just snap into place. Less hassle, and more consistent performance.

Q-LED Core

The Q-LED Core display produces colour-coded lights during the Power-On Self-Test (POST) that can help you troubleshoot potential issues.

• No CPU detected - fast blinking 4 Hz (0.25 s)
• No VGA detected - slow blinking 1/2 Hz (2 s)
• No boot device detected - very slow blinking 1/8 Hz (8 s)
• Installation completed - solid light

Pre-Mounted I/O Shield

Our pre-installed I/O shield safeguards ports, simplifies the build process, increases functionality and enhances aesthetics for PC DIY enthusiasts.

BIOS FlashBack^™

BIOS FlashBack^™ simplifies BIOS updates. Just load the BIOS file onto a FAT32 USB stick, insert it into the BIOS FlashBack^™ port, and press a button—no CPU or memory needed.

SafeSlot Core+

SafeSlot Core+ is a one-piece stainless-steel brace that shields the slot to protect it from damage. The metal cover is tightly secured to the slot with hooks, and the entire assembly is firmly anchored to the PCB with strengthened solder points to provide a secure foundation for heavyweight graphics cards.

Build for the Most Advanced PC for Gaming and Creating

When only the fastest will do, ASUS motherboards deliver. With faster dual-channel DDR5 memory support, AMD EXPO^™ technology and PCIe^® 4.0 support for both graphics and NVMe, you can play the most demanding games and deliver your biggest projects with the revolutionary performance of an ASUS motherboard and AMD Ryzen^™ 9000, 8000, and 7000 Series processors.