Description
The ASUS Prime B840M‑A WiFi CSM is designed for compact yet powerful AMD AM5 builds. It includes a reliable 8+2+1 power stage design with VRM heatsinks and hybrid fan headers, supporting Ryzen 7000/8000/9000 CPUs. Memory support extends to 256 GB DDR5, overclockable to 7600 MT/s using EXPO or AEMP profiles. The board features a full-length PCIe 4.0 x16 slot alongside three M.2 slots (two PCIe 4.0, one PCIe 3.0) all with heatsinks, and four SATA ports. Networking is robust, with 2.5 Gb Ethernet, dual-band Wi‑Fi 6E, and Bluetooth 5.3. Rear I/O includes dual DisplayPort, HDMI, multiple USB ports including Type‑C, and audio jacks with a FlashBack BIOS button. Aura Sync RGB lighting with Gen 2 headers and Static-Q fan and build optimizations complete a system built for stability and scalability.

Key Features

• AM5 socket supporting Ryzen 7000/8000/9000 series

• 8+2+1 digital power stages with VRM heatsink

• Dual-channel DDR5 up to 256 GB, 7600+ MT/s OC via EXPO/AEMP

• PCIe 4.0 x16 GPU slot; 3× M.2 slots with heatsinks, 4× SATA 6 Gb/s

• Intel Wi‑Fi 6E (2×2, 2.4/5/6 GHz); Bluetooth 5.3; Realtek 2.5 Gb LAN

• Rear USB: Type‑C (5 Gbps), 2× USB 10 Gbps, 4× USB 5 Gbps, 4× USB 2.0; Thunderbolt 4 header

• Dual DisplayPort and HDMI outputs

• Realtek 7.1 HD audio; BIOS FlashBack

• Cooling: VRM heatsink; 4× hybrid fan/AIO headers

• Aura Sync RGB with 3× addressable Gen 2 headers

• Pre-mounted I/O, SafeSlot Core+, Q‑Antenna, Q‑LED, BIOS FlashBack

Key Specifications

• Form Factor: Micro‑ATX (244 × 244 mm)

• Chipset: AMD B840

• CPU Support: Ryzen 7000/8000/9000

• Memory: 4× DDR5 DIMM, 256 GB max, up to 7600 MT/s OC

• Expansion: 1× PCIe 4.0 x16; 2× PCIe 3.0 x16 (x1)

• Storage: 2× M.2 PCIe 4.0 x4; 1× M.2 PCIe 3.0 x4; 4× SATA 6 Gb/s

• Networking: Wi‑Fi 6E, Bluetooth 5.3, Realtek 2.5 Gb Ethernet

• USB I/O: 1× Type‑C 5 Gbps; 2× 10 Gbps USB; 4× 5 Gbps USB; 4× USB 2.0

• Video: 2× DisplayPort; 1× HDMI

• Audio: Realtek 7.1 HD codec

• Cooling & Headers: VRM heatsink; CPU, chassis, AIO fan headers

• RGB: Aura Sync + 3× addressable Gen 2 headers