Asus PRIME B840M-A-CSM AM5 Micro ATX Motherboard

Description

Quick Specs

• Supports AMD Ryzen 7000/8000/9000 Series Desktop Processors.
• Features a PCIe 4.0 slot for lightning-fast gaming experiences.
• Includes SafeSlot Core+ for enhanced PCIe slot retention and durability.
• Simplifies builds with Q-LED Core for easy troubleshooting.
• Offers BIOS FlashBack for convenient BIOS updates.

Built for AMD Ryzen Processors

Designed to fully support the latest AMD Ryzen 7000, 8000 and 9000 Series desktop processors, the ASUS B840M AM5 Motherboard is ready to deliver exceptional computing power. Ideal for gamers, content creators, and anyone seeking a high-performance PC, it ensures seamless compatibility and optimised performance with your chosen Ryzen CPU.

Experience Lightning-Fast Gaming with this ASUS AM5 Motherboard

The PCIe 4.0 slot provides double the bandwidth compared to the previous generation, unlocking lightning-fast speeds for modern GPUs and NVMe SSDs. Gamers will appreciate reduced loading times and smoother gameplay, while creative professionals can benefit from quicker data transfers for large files and complex projects. This AM5 Micro ATX Motherboard is built to handle it all.

EZ PC DIY Features

Building or upgrading your PC is now easier than ever with ASUS's innovative DIY-friendly features. SafeSlot Core+ provides stronger PCIe slot retention and greater shearing resistance, ensuring your graphics card stays securely in place. Q-LED Core simplifies troubleshooting by indicating potential issues with key components, while the pre-mounted I/O shield streamlines installation and protects against electrostatic discharge.

Stay Cool and Reliable

Effective thermal management is essential for maintaining peak performance, and this ASUS AM5 Motherboard is equipped with comprehensive cooling solutions. Multiple heatsinks and strategically placed fan headers keep temperatures in check, preventing thermal throttling and ensuring long-term reliability, even under heavy workloads.

Future-Proof Connectivity

With a range of USB ports, including USB Type-C, this B840M AM5 Micro ATX Motherboard offers versatile connectivity options for all your peripherals and devices. Fast Ethernet ensures reliable network performance for online gaming and seamless streaming, while high-definition audio delivers immersive sound quality for an enhanced entertainment experience.

FEATURES:

• Intel B840M Chipset
• Supports AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors
• Supports DDR5 Memory, Dual Channel DDR5 7600+ MT/s (OC) 256GB max capacity
• Ultra-fast Realtek 2.5G Ethernet LAN
• Lightning Fast Game experience: PCIe 4.0 slot support
• Asus Fan Xpert 2+ for more cooling control
• EZ PC DIY: SafeSlot Core+ and Q-LED Core, BIOS Flashback, and a pre-mounted I/O shield for easy usage
• Aura Sync support for full RGB lighting control

SPECIFICATIONS:

• CPU:
  • AMD Socket AM5 for AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors*
  • * Refer to for CPU support list.
• Chipset: AMD B840 Chipset
• Memory:
  • 4 x DIMM slots, max. 256GB, DDR5
  • Supports up to 7600+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)
  • * Supported memory types, data rate (speed), and number of DRAM modules vary depending on the CPU and memory configuration
  • * Non-ECC, un-buffered DDR5 memory supports On-Die ECC function.
• Graphics:
  • 2 x DisplayPort**
  • 1 x HDMI™ port***
  • * Graphics specifications may vary between CPU types. Please refer to AMD CPU specifications.
  • ** Supports max. 8K@30Hz as specified in DisplayPort 1.4.
  • *** Supports 4K@60Hz as specified in HDMI 2.1.
• Expansion Slots:
  • 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)**
  • AMD B840 Chipset
  • 2 x PCIe 3.0 x16 slots (support x1 mode)
  • * Please check the PCIe bifurcation table on the support site (
  • ** Specifications vary by CPU types.
  • To ensure compatibility of the device installed, please refer to for the list of supported peripherals.
• Storage:
  • Total 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 4.0 x4 mode)
  • M.2_2 slot (Key M), type 2242/2260/2280 (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 2242/2260/2280 (supports PCIe 4.0 x4/x2 mode)*
  • AMD B840 Chipset
  • M.2_3 slot (Key M), type 2280 (supports PCIe 3.0 x4 mode)
  • 4 x SATA 6Gb/s ports
  • * Specifications vary by CPU types.
• RAID:
  • AMD RAIDXpert2 Technology
  • Ryzen™ 9000 Series Processors: RAID 0/1/5/10
  • Ryzen™ 8000 Series Processors: RAID 0/1
  • Ryzen™ 7000 Series Processors: RAID 0/1/10
• Ethernet:
  • 1 x Realtek 2.5Gb Ethernet
  • ASUS LANGuard
• Rear USB (Total 7 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)
• 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
  • * USB Type-C® power delivery output: max. 5V/3A
• 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
  • *A chassis with an HD audio module in the front panel is required to support 7.1 Surround Sound audio output.
• Back Panel 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 Realtek 2.5Gb Ethernet port
  • 3 x Audio jacks
  • 1 x BIOS FlashBack™ button
• Operating System: Windows 11, Windows 10 64-bit
• Form Factor: Micro ATX

WHAT’S IN THE BOX:

• Asus PRIME B840M-A-CSM AM5 Micro ATX Motherboard – Black x1
• SATA Cables x2
• M.2 rubber package x1
• Screw Package for M.2 SSD x2
• Quick Start Guide x1

Why Asus?

ASUS is a globally recognised tech company renowned for quality and innovation. For over three decades, ASUS has consistently delivered cutting-edge PC components and electronics, earning the trust of gamers, professionals, and everyday users alike. Choose ASUS for reliability, performance, and a commitment to pushing the boundaries of what's possible. When building your next PC, an ASUS AM5 motherboard is a solid foundation.