PRIME B550M-A/CSM

AMD B550 (Ryzen AM4) micro ATX motherboard with dual M.2, PCIe 4.0, 1 Gb Ethernet, HDMI/D-Sub/DVI, SATA 6 Gbps, USB 3.2 Gen 2 Type-A, and Aura Sync RGB headers support
  • Ready for Advanced AI PC: Designed for the future of AI computing, with the power and connectivity needed for demanding AI applications
  • AMD AM4 socket: Ready for Ryzen™ 5000 Series/ 4000 G-Series/ 3000 Series Desktop Processors
  • Comprehensive cooling: VRM heatsink, PCH heatsink, and Fan Xpert 2+
  • Ultrafast connectivity: Dual M.2, PCIe 4.0, 1 Gb Ethernet, USB 3.2 Gen 2 Type-A
  • Aura Sync RGB: Onboard addressable Gen 2 header for RGB LED strips, easily synced with Aura Sync-capable hardware
Win11
Ready For Advanced AI PC
PRIME B550M-A/CSM
PRIME B550M-A front view
TUF H370 Plus Gaming TUF H370 Plus Gaming
  • PS/2

  • 2 x USB 3.2 Gen 1

  • DVI-D

  • D-Sub

  • HDMI

  • 2 x USB 3.2 Gen 2

  • Realtek LAN

  • 2 x USB 3.2 Gen 1

  • 3 x Audio jacks

  • PCIe 4.0 x16
    ASUS SafeSlot Core

  • Audio Features
    ● LED-illuminated design
    ● Audio Shielding
    ● Premium Audio Capacitors
    ● Dedicated Audio
    PCB Layers

  • Addressable Gen 2 header

  • DIGI+ VRM & EPU

  • DDR4 support

  • AMD AM4 socket for Ryzen™ 5000 Series/ 4000 G-Series/ 3000 Series Desktop Processors

  • 2 x Front USB 3.2 Gen 1

  • 64Gb/s M.2 Support
    PCIe 4.0 x4 & SATA mode

  • AMD B550 Chipset

  • 32Gb/s M.2 Support
    PCIe 3.0 x4 & SATA mode

  • 4 x SATA 6Gb/s

  • 4 x Front USB 2.0

  • 2 x AURA RGB headers

ASUS Prime series is expertly engineered to unleash the full potential of 3rd Generation AMD Ryzen platform. Boasting a robust power design, comprehensive cooling solutions and intelligent tuning options, Prime B550 series motherboards provide daily users and DIY PC builders a range of performance tuning options via intuitive software and firmware features. This platform delivers the power and connectivity that advanced AI PC applications demand.

AMD Ryzen, Advanced AI PC ready's icon

ASUS Corporate Stable Model

ASUS Corporate Stable Model (CSM) is a commercial program 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 organization to get ready for product transitions. Each purchase of an ASUS CSM motherboard comes with ASUS Control Center Express - server-grade IT management software.

Learn more about ASUS Corporate Stable Model >

* Lifecycle support for consumer chipsets (eg. Q370, H370, B360,H270,B250) is set at 15 months. Program offerings 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-optimized solution for your business needs.

Learn more about ASUS Control Center Express >

Optimize 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

Tune It Your Way

Comprehensive controls form the foundation of the ASUS Prime series. The Prime B550 motherboard packs flexible tools to tune every aspect of your system, enabling you to tweak performance settings to perfectly match the way you work – maximizing your productivity.

All-around Energy Efficiency

With the Energy Processing Unit (EPU), you'll enjoy system-wide power savings. The EPU automatically optimizes power consumption and maximizes savings with Away mode.

Flexible Cooling Controls

Fan Xpert 2+ software provides comprehensive control over system fans. 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.

Precise Digital Power Control

The Digi+ voltage-regulator module (VRM) delivers real-time control over voltage droop, automatically switching frequency and power-efficiency settings. It also allows you to fine-tune your CPU for ultimate stability and performance.

Back to Tune It Your Way

UEFI BIOS

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.

Advanced Tuning for Serious Tweakers

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.

Search Function
Quickly and easily find the option or setting you need.

ASUS User Profile
Port configuration settings between different BIOS versions or share them with friends.

Quick and Simple Setup

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.

EZ XMP
Improve DRAM performance with one click.

Aura On/Off mode (Stealth)
Easily enable or disable Aura RGB lighting or every onboard LED, for a subdued aesthetic touch.

Back to Tune It Your Way

Cool to the Core

Prime B550 series is engineered with multiple onboard heatsinks and an array of hybrid fan headers to ensure your rig stays cool and stable under intense workloads.

VRM Heatsink and Thermal Pads

A VRM heatsink with underneath thermal pad improves heat transfer from the MOSFETs and chokes for better cooling performance.

VRM Heatsink and Thermal Pads

Two massive VRM heatsinks with underneath thermal pads improve heat transfer from the MOSFETs and chokes for better cooling performance. A bundled fan holder provides additional cooling options.

Stack Cool 3+

2oz-copper layers shift heat away from critical components, reducing the temperature by up to 20°C.

Back to Cool to the Core

Cooler by Design

Prime B550 series features comprehensive cooling controls that are configurable via Fan Xpert 2+ software or via the UEFI BIOS.

  • Multiple Temperature Sources
  • Smart Protection
  • 4-Pin PWM/DC Fan
  • Each header can dynamically reference three thermal sensors. Fan Xpert 2+ allows you to map the temperature of supported ASUS graphics cards to optimize cooling for GPU- and CPU-intensive tasks.

  • A dedicated integrated circuit protects each fan header from overheating and overcurrent.

  • Each onboard chassis fan header supports PWM and DC mode.

Back to Cool to the Core

Build on a Solid Foundation

Prime B550 motherboard provides all the fundamentals to boost daily productivity, so your system will be ready for action with stable power, intuitive cooling and flexible transfer options.

ProCool Connectors

Proprietary connectors augment the motherboard's link to the PSU with 8+4 pin connectors that pass 12 volts of power directly to the processors. The jacks feature solid pins that can handle more current than hollow-pin connectors.

10+1 DrMOS Power Stages

A VRM with 10+1 DrMOS Power Stages delivers the power and efficiency that the latest Intel processors demand.

Back to Build on a Solid Foundation

ASUS OptiMem II

Revisions to the motherboard's trace routing provide the latest Intel processors with unrestricted access to memory bandwidth. ASUS OptiMem II technology carefully maps memory signal pathways across different PCB layers to reduce vias and adds shielding zones that significantly reduce crosstalk.

Top layer – ground ring to prevent lateral interference

ASUS OptiMem II benefits:

  • Improved memory stability and compatibility
  • Allows lower memory latencies at equivalent voltages
  • Improved memory frequency margin

Motherboards with OptiMem II technology were tested with Synopsys HSPICE simulation software

Back to Build on a Solid Foundation

PCIe 4.0 M.2
(up to 64 Gbps)

Achieve speed with onboard M.2

PCIe 4.0 M.2 Slot supports up to 22110 and provide NVMe SSD RAID support for an incredible performance boost. Create a RAID configuration with up to PCIe 4.0 storage device to enjoy the fastest data-transfer speeds on the 3rd Generation AMD Ryzen platform.

Back to Build on a Solid Foundation

Intel® WiFi 6 AX200

The Intel® WiFi 6 AX200 module is compatible with the 802.11ax standard and pushes theoretical peak bandwidth up to an incredible 2.4 Gbps. Perhaps more importantly for power users, it's optimized for more efficient operation on crowded networks with a lot of competing traffic. Pair your motherboard with ASUS WiFi 6 routers to fully experience the networking potential of WiFi 6.

Learn more >
Intel WiFi 6 AX200
2.4 Gbps
Other wireless adapters
0.86 Gbps

* Actual speed varies, and depends on networking conditions.

Back to Get the Most out of All Your Cores

USB 3.2 Gen 2
Type-A

Numerous USB ports support high-end rigs loaded with peripherals, including two rear-panel USB Type-A connectors with fast USB 3.2 Gen 2 connectivity for compatible cases.

Back to Build on a Solid Foundation

Little Things Make a Big Difference

Prime B550 series adds the nuanced details that improve every experience, from exclusive codecs that provide pristine audio quality to intuitive RGB lighting controls that let you customize your system to create a uniquely personal look.

Overvoltage Protection

World-class circuit-protecting power design

An exclusive circuit design with built-in voltage regulators to protect your motherboard from damage caused by unexpected high-level voltages from unstable or inferior power supplies.

DRAM Overcurrent Protection

Short-circuit damage prevention

Onboard resettable fuses prevent overcurrent and short-circuit damage. This extends beyond I/O ports to DRAM to safeguard the lifespan of your system and connected devices.

Stainless-Steel Back I/O

3X corrosion-resistance for greater durability

Corrosion-resistant stainless-steel back I/O panels bonded with chromium oxide have a lifespan that's three times longer than ordinary panels.

LANGuard

Pumped-up throughput 2.5X higher surge tolerance

ASUS LANGuard is a hardware-level network protection feature that integrates advanced signal-coupling technology and premium anti-EMI surface-mounted capacitors to improve throughput and ensure a more reliable connection.

Learn more

1000+

Compatible devices and components

The Prime B550 series provides superior compatibility with thousands of components and our Qualified Vendor List (QVL) identifies memory compatibility, giving you more choices for worry-free PC-building experiences.

8000+

Validation hours

Every ASUS motherboard is subjected to more than 8,000 hours of stringent tests, including burn-in, environmental, compatibility, software and safety tests to confirm their durability. ASUS reliability surpasses industry standards, ensuring that every component is designed to function flawlessly in any environment.

Temperature and humidity tests
Ensures components withstand extreme conditions.
Thermal measurement tests
Ensures that the system remains cool and stable under the heaviest loads.
Insertion tests
Every port and connector is put through repeated installation cycles.
Aging tests
Up to 48-hour aging test ensures reliability.
Power-consumption tests
Checked for world-class energy efficiency.
Temperature and DC margin tests
Ensures that the motherboard is capable of coping with voltages fluctuations caused by varying temperatures.
Thermal-shock tests
Ensures ability to survive temperature changes during transportation.
Non-operation shock tests
Built to withstand jolts that may occur during shipping.
Burn-in tests
Every component is checked to ensure flawless operation.
Installation tests
Connector placement is double-checked to ensure hassle-free installation.
Drop tests
Drop tests from various heights ensure durability.
Salt and spray tests
Tested for I/O reliability, prolonged lifespan and rust-resistance.

Outstanding Audio

Combined onboard features deliver elevated audio

Intelligent design and premium hardware create audio quality unlike anything you've ever experienced.

Audio Shielding

Separates analog/digital signal domains, significantly reducing multi-lateral interference.

Separate Layer for Left and Right Tracks

Ensures minimal crosstalk between audio paths.

Premium Audio Capacitors

Premium parts provide an immersive sound signature, with exceptional fidelity.


Flawless Audio that Immerses You in the Game

Power Pre-Regulator

Reduces power-input noise to ensure consistent performance.

Audio Shielding

Separates analog/digital signal domains, significantly reducing multi-lateral interference.

Separate Layer for Left and Right Tracks

Ensures minimal crosstalk between audio paths.

Integrated Amplifier

Capable of driving high-impedance headphones, without rolling-off high or low frequencies.

De-Pop Circuit

Reduces start-up popping noise to all audio outputs.

Premium Japanese Capacitors

Premium parts provide an immersive sound signature, with exceptional fidelity.

Back to Little Things Make a Big Difference

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 RGB LED strips connected to the onboard RGB headers. And it can all be synced with an ever-growing portfolio of Aura-capable hardware.

Learn more >
  • Static Static
  • Breathing Breathing
  • Strobing Strobing
  • Rainbow Rainbow
  • Color cycle Color Cycle
  • Starry night Starry Night
  • Music effect Music Effect
  • CPU temperature Smart

Addressable Gen 2 RGB Header

The addressable Gen 2 RGB header is now capable of detecting the number of LEDs on second-gen addressable RGB devices, allowing the software to automatically tailor lighting effects to specific devices. The new header also offers backward-compatibility with existing Aura RGB gear.

Armoury Crate

Armoury Crate is a new software utility designed to give you centralized control of supported products. From a single intuitive interface, Armoury Crate allows you to easily customize RGB lighting and effects for every compatible device in your arsenal. The software also provides control of settings for ASUS products, including keyboard and mouse preferences. Armoury Crate even features dedicated product registration and highlight to help you stay in touch with the ASUS community.


  • Aura Sync

  • Driver & Manual Download

  • Account Management

Back to Little Things Make a Big Difference
Back to Little Things Make a Big Difference
Recommend for you
PRIME B550M-A (WI-FI)/CSM
PRIME B550M-A (WI-FI)/CSM
PRIME B550M-A (WI-FI)/CSM
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX motherboard, Advanced AI PC ready, dual M.2, PCIe 4.0, Intel® WiFi 6, 1 Gb Ethernet, HDMI/D-Sub/DVI, SATA 6 Gbps, USB 3.2 Gen 2 Type-A, and Aura Sync RGB headers support
PRIME B550M-A/CSM
PRIME B550M-A/CSM
PRIME B550M-A/CSM
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX motherboard, Advanced AI PC ready, dual M.2, PCIe 4.0, 1 Gb Ethernet, HDMI/D-Sub/DVI, SATA 6 Gbps, USB 3.2 Gen 2 Type-A, and Aura Sync RGB headers support
PRIME B550M-K/CSM
PRIME B550M-K/CSM
PRIME B550M-K/CSM
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX motherboard, Advanced AI PC ready, dual M.2, PCIe 4.0, 1 Gb Ethernet, HDMI/D-Sub/DVI, SATA 6 Gbps, USB 3.2 Gen 2 Type-A
PRIME A520M-A/CSM
PRIME A520M-A/CSM
PRIME A520M-A/CSM
Win11
0.0 out of 5 stars.
AMD A520 (Ryzen AM4) micro ATX motherboard with M.2 support, 1 Gb Ethernet, HDMI/DVI/D-Sub, SATA 6 Gbps, USB 3.2 Gen 1 Type-A
TUF GAMING B550M-E WIFI
TUF GAMING B550M-E WIFI
TUF GAMING B550M-E WIFI
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX gaming motherboard, Advanced AI PC ready, dual M.2, Intel® WiFi 6, 1 Gb Ethernet, HDMI, DisplayPort, D-Sub, SATA 6 Gbps, USB 3.2 Gen 2 Type-A, front USB 3.2 Gen 1 Type-C®, BIOS FlashBack™, and Aura Sync RGB lighting support
TUF GAMING B550M-E
TUF GAMING B550M-E
TUF GAMING B550M-E
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX gaming motherboard, Advanced AI PC ready, dual M.2, 1 Gb Ethernet, HDMI, DisplayPort, D-Sub, SATA 6 Gbps, USB 3.2 Gen 2 Type-A, front USB 3.2 Gen 1 Type-C®, BIOS FlashBack™, and Aura Sync RGB lighting support
Pro B550M-C/CSM
Pro B550M-C/CSM
Pro B550M-C/CSM
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX business motherboard with enhanced security, reliability and manageability. Dual M.2, PCIe 4.0, 1 Gb Ethernet, dual DP/HDMI, SATA 6 Gbps, USB 3.2 Gen 2 Type-C®.
PRIME B450M-A II/CSM
PRIME B450M-A II/CSM
PRIME B450M-A II/CSM
Win11
0.0 out of 5 stars.
AMD B450 (Ryzen AM4) micro ATX motherboard with M.2 support, HDMI/DVI-D/D-Sub, SATA 6 Gbps, 1 Gb Ethernet, USB 3.2 Gen 2 Type-A, BIOS FlashBack™, and Aura Sync RGB lighting support
PRIME B450M-A II
PRIME B450M-A II
PRIME B450M-A II
Win11
0.0 out of 5 stars.
AMD B450 (Ryzen AM4) micro ATX motherboard with M.2 support, HDMI/DVI-D/D-Sub, SATA 6 Gbps, 1 Gb Ethernet, USB 3.2 Gen 2 Type-A, BIOS FlashBack™, and Aura Sync RGB lighting support
TUF GAMING B450M-PRO II
TUF GAMING B450M-PRO II
TUF GAMING B450M-PRO II
Win11
0.0 out of 5 stars.
AMD B450 (AM4) micro ATX gaming motherboard with dual M.2, PCIe 3.0, AI Noise-Canceling Microphone, HDMI, DisplayPort, USB 3.2 Gen 2 Type-A and Type-C and Aura Sync RGB lighting support
TUF GAMING B450M-PLUS II
TUF GAMING B450M-PLUS II
TUF GAMING B450M-PLUS II
Win11
0.0 out of 5 stars.
AMD B450 (AM4) micro ATX gaming motherboard with M.2 support, AI Noise-Canceling Microphone, HDMI, DVI-D, USB 3.2 Gen 2 Type-A, USB 3.2 Gen 1 Type-A and Type-C, Aura Sync RGB lighting support
award iconaward iconaward icon
PRIME B550M-K
PRIME B550M-K
PRIME B550M-K
Win11
Ready For Advanced AI PC
0.0 out of 5 stars.
AMD B550 (Ryzen AM4) micro ATX motherboard, Advanced AI PC ready, dual M.2, PCIe 4.0, 1 Gb Ethernet, HDMI/D-Sub/DVI, SATA 6 Gbps, USB 3.2 Gen 2 Type-A
previous image
next image
Related products
previous image
next image
comparison icon
Compare (0)