Sale!

ASUS PRIME B850M-A-CSM Socket AM5 DDR5 Micro ATX Motherboard

Original price was: £115.09.Current price is: £80.56.

  • Part Number: 90MB1LQ0-M0EAYC
  • Form Factor & Socket: Micro-ATX | AMD AM5 Socket (Ryzen 9000 / 8000 / 7000 Series) | AMD B850 Chipset
  • Memory & Storage: 4x DDR5 DIMM Slots (AEMP & EXPO Support) | 3x M.2 Slots (1x PCIe 5.0, 2x PCIe 4.0)
  • Expansion: 1x PCIe 5.0 x16 SafeSlot | 1x PCIe 4.0 x16 (x1 mode)
  • Networking & Connectivity: Wi-Fi 6E | Realtek 2.5Gb Ethernet | Front USB 5Gbps Type-C | Rear USB 10Gbps Type-C
  • Key Features: 8+2+1 Phase Digital Power Design | Pre-mounted I/O Shield | BIOS FlashBack™ | Q-Antenna | Aura Sync RGB | CSM with 36-Month Lifecycle Support & Control Center Express
  • Warranty: 3 Years

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✅ Authorized Retailer | Official Local Warranty in Egypt | Fast Shipping

ASUS · PRIME · AM5 · B850 · MICRO ATX

ASUS PRIME B850M-A-CSM Socket AM5 DDR5 Micro ATX Motherboard

AMD B850 · AM5 · DDR5 · PCIe 5.0 · 8+2+1 Phase · WiFi 6E · 2.5Gb Ethernet

ASUS PRIME B850M-A-CSM Micro ATX Motherboard - Front View

AM5
Socket

DDR5
Memory

PCIe 5.0
Ready

WiFi 6E
Wireless

The ASUS PRIME B850M-A-CSM is a Micro ATX motherboard engineered for AMD Ryzen 9000, 8000, and 7000 series processors. Built on the AMD B850 chipset with the AM5 socket, it delivers advanced AI PC readiness, comprehensive DDR5 memory tuning, and PCIe 5.0 support for next-generation graphics and storage. Additionally, the 8+2+1 phase digital power design ensures stable, efficient power delivery, while WiFi 6E and Realtek 2.5Gb Ethernet provide ultrafast connectivity. With three M.2 slots, USB 5Gbps Type-C front panel support, and BIOS FlashBack, this motherboard is ready for business and enthusiast builds alike. Furthermore, it is backed by a 3-Year Local Warranty and belongs to ASUS’s CSM program, which guarantees 36-month stable supply.

Product Gallery

Key Features of ASUS PRIME B850M-A-CSM

⚡

8+2+1 Phase Power

Stable power delivery for AMD Ryzen

🧠

AI PC Ready

Optimized for AI workloads

📶

WiFi 6E + 2.5Gb Ethernet

Ultrafast wireless and wired connectivity

🔌

PCIe 5.0 Support

For next-gen GPUs and NVMe SSDs

💾

3x M.2 Slots

Up to 128 Gbps data-transfer speeds

🛡️

CSM Ready

36-month stable supply program

In the Box

Everything included with your ASUS PRIME B850M-A-CSM

🖥️
PRIME B850M-A-CSM

Micro ATX Motherboard · AM5

📶
WiFi Antenna

Q-Antenna · Easy attach

🔧
SATA Cables

2x SATA 6Gbps cables

📄
User Manual

Quick-start guide

Advanced AI PC Ready

Engineered for AMD Ryzen 9000 series processors, the ASUS PRIME B850M-A-CSM unlocks the full potential of advanced AI workloads. Moreover, it provides users and PC DIY builders with a range of performance optimizations via intuitive software and firmware features. Consequently, the motherboard is fully Advanced AI PC-ready, offering both the power and connectivity needed for demanding AI applications.

AI Ready
Ryzen 9000
AM5

8+2+1 Phase Digital Power Design

Featuring an 8+2+1 phase power design with discrete MOSFETs, this motherboard ensures efficient and stable power delivery for AMD processors. In addition, the six-layer PCB design enhances stability and overclocking capabilities. As a result, users enjoy steady performance even during day-to-day use.

8+2+1 Phase
Discrete MOSFETs
6-Layer PCB

💡 Build Insight

Pro Tip: Optimize Your AM5 Build

For maximum performance, enable AMD EXPO in BIOS for optimal DDR5 speeds. Use the AI Cache Boost feature to supercharge LLM workflows. Meanwhile, the BIOS FlashBack button makes updating the BIOS simple — no CPU or memory needed. Pair with a high-quality AM5 CPU cooler for best thermal performance.

⚙️ AMD EXPO
🧠 AI Cache Boost
🔄 BIOS FlashBack

Enhanced DDR5 & Storage Performance

Comprehensive memory tuning options maximize the potential of your DDR5 modules. For example, ASUS Enhanced Memory Profile (AEMP) automatically detects memory chips and provides optimized profiles. Additionally, with three M.2 slots including PCIe 5.0 support, enjoy up to 128 Gbps data-transfer speeds for quicker boot-up and app load times.

DDR5
AEMP
3x M.2

Empowering Connectivity

This motherboard offers a versatile range of connectivity options. Specifically, it includes WiFi 6E technology with triple the bandwidth, Realtek 2.5Gb Ethernet for faster data transfers, and PCIe 5.0 slot support. Furthermore, an arsenal of USB ports is available, including USB 5Gbps and 10Gbps Type-C connections. Additionally, the Q-Antenna attaches quickly with a snap for easy WiFi setup.

WiFi 6E
2.5Gb Ethernet
USB Type-C

DIY Friendly — EZ PC DIY

Built with EZ PC DIY innovations, the PRIME B850M-A-CSM simplifies PC building. For example, the Q-Antenna attaches quickly with a snap. In addition, the pre-mounted I/O shield safeguards ports and simplifies installation. Meanwhile, BIOS FlashBack allows easy BIOS updates without CPU or memory, and SafeSlot ensures secure PCIe 5.0 card installation.

Q-Antenna
BIOS FlashBack
SafeSlot

Best For & Considerations

✅ Best For

  • ✔ AMD Ryzen 9000/8000/7000 Series builds
  • ✔ Micro ATX compact PC builds
  • ✔ Business and corporate stable systems (CSM)
  • ✔ AI-enabled workloads and LLM applications
  • ✔ Users needing PCIe 5.0 & WiFi 6E connectivity

❌ Considerations

  • ✗ Users needing ATX full-size motherboards
  • ✗ Those who prefer Intel platforms (AM5 only)
  • ✗ Builds requiring multiple PCIe x16 slots
  • ✗ Users needing more than 4 RAM slots

Technical Specifications

Model Name ASUS PRIME B850M-A-CSM
SKU 90MB1LQ0-M0EAYC
UPC 199291054721
CPU Socket AM5 (AMD Ryzen 9000/8000/7000)
Chipset AMD B850
Form Factor Micro ATX
Memory 4x DDR5 DIMM · Dual Channel · AEMP
PCIe Slots 1x PCIe 5.0 x16 · 1x PCIe 4.0 x16 (x1 mode)
M.2 Slots 3x M.2 (1x PCIe 5.0 x4, 2x PCIe 4.0 x4)
Power Design 8+2+1 Phase Digital VRM
Networking WiFi 6E · Realtek 2.5Gb Ethernet
USB Ports USB 5Gbps Type-C · USB 10Gbps Type-C
Special Features BIOS FlashBack · Q-Antenna · Pre-mounted I/O Shield · Aura Sync
CSM Program Up to 36-month stable supply
Official Warranty 3 Years Local Warranty

Platform Compatibility

AMD Ryzen 9000 Series
✓ Supported
AMD Ryzen 8000 Series
✓ Supported
AMD Ryzen 7000 Series
✓ Supported
DDR5 Memory (AEMP)
✓ Supported
PCIe 5.0 Graphics Cards
✓ Supported
PCIe 5.0 NVMe SSDs
✓ Supported

Frequently Asked Questions

What CPUs are compatible with the PRIME B850M-A-CSM?
+
The PRIME B850M-A-CSM supports AMD Ryzen 9000, 8000, and 7000 Series processors using the AM5 socket. Therefore, please check the ASUS website for the complete CPU compatibility list.
What is the ASUS CSM program?
+
ASUS Corporate Stable Model (CSM) is a commercial program offering up to 36-month product lifecycle support and 6-month end-of-life notice. Additionally, each purchase comes with ASUS Control Center Express — server-grade IT management software.
Does this motherboard support DDR5 memory overclocking?
+
Yes. The PRIME B850M-A-CSM supports DDR5 memory with AMD EXPO profiles and ASUS Enhanced Memory Profile (AEMP) for automatic memory tuning. In addition, it offers extensive UEFI settings for further performance tweaks.
How many M.2 slots does this motherboard have?
+
The PRIME B850M-A-CSM features three M.2 slots: one PCIe 5.0 x4 (2280) and two PCIe 4.0 x4 (2280 and 2242/2260/2280). As a result, you can enjoy up to 128 Gbps data-transfer speeds.
What is BIOS FlashBack and how does it work?
+
BIOS FlashBack allows you to update the BIOS without installing a CPU, memory, or graphics card. Specifically, load the BIOS file onto a FAT32 USB stick, insert it into the BIOS FlashBack port, and press the button for a quick and easy BIOS update.

Alfrensia — Egypt’s trusted destination for premium PC hardware since 2006

⚡ Prices & specifications subject to change. Please verify before purchase.

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