ASUS PRIME B840M-A WIFI-CSM AM5 M-ATX Motherboard

Overview

The ASUS PRIME B840M-A WIFI-CSM is a micro ATX motherboard designed for AMD AM5 socket processors, supporting Ryzen 7000, 8000, and 9000 series CPUs. It offers a compact form factor that fits well in smaller cases while providing extensive expansion options for gaming, content creation, and professional use. With support for up to 192 GB of DDR5 memory at speeds reaching 7600 MT/s, this board delivers the bandwidth needed for demanding applications and multitasking.

Storage options include three M.2 slots—two PCIe 4.0 and one PCIe 3.0—alongside four SATA III ports, allowing for a versatile combination of fast NVMe drives and high-capacity storage. The motherboard also features multiple PCIe slots for graphics cards and peripherals, integrated Wi-Fi 6E and Bluetooth 5.3 for wireless connectivity, and a 2.5 Gb Ethernet port for reliable wired networking.

Key features

• AM5 socket compatibility with Ryzen 7000, 8000, and 9000 series processors, enabling future upgrades without changing the motherboard
• Four DDR5 DIMM slots supporting up to 192 GB of high-speed memory at 7600 MT/s, ensuring smooth performance in memory-intensive tasks
• Three M.2 slots for flexible storage setups, including two PCIe 4.0 NVMe drives for fast boot and load times, plus one PCIe 3.0 slot for additional storage
• Dual PCIe 4.0 x16 slots for high-performance graphics cards or compute accelerators, plus two PCIe 3.0 x16 slots operating at x1 for sound cards or network adapters
• Integrated HDMI 2.1 and DisplayPort 1.4 outputs to support display connectivity without requiring a discrete GPU, ideal for office or media setups
• Wi-Fi 6E tri-band and Bluetooth 5.3 provide fast and stable wireless connections for peripherals and internet access
• Realtek 2.5 Gb Ethernet port delivers low-latency wired networking suitable for gaming and professional workloads
• Rear USB ports include a 10 Gb/s Type-A and a 5 Gb/s Type-C connector, supporting fast data transfer and charging for modern devices
• BIOS FlashBack button allows easy firmware updates without needing a CPU installed, simplifying maintenance and upgrades
• Realtek 7.1-channel audio codec supports 24-bit, 192 kHz playback for clear and detailed sound in calls, music, and movies

Key specs

• Chipset: AMD B840
• Socket: AM5
• Memory: 4x DDR5 DIMM slots, up to 192 GB, 7600 MT/s
• Storage: 3x M.2 slots (2x PCIe 4.0, 1x PCIe 3.0), 4x SATA III ports
• Expansion slots: 2x PCIe 4.0 x16, 2x PCIe 3.0 x16 (x1 mode)
• Video outputs: HDMI 2.1, DisplayPort 1.4
• Networking: Wi-Fi 6E tri-band, Bluetooth 5.3, Realtek 2.5 Gb Ethernet
• USB ports: Rear USB 10 Gb/s Type-A, USB 5 Gb/s Type-C
• Audio: Realtek 7.1-channel codec, 24-bit/192 kHz playback

Connectivity and compatibility

This motherboard supports a wide range of modern connectivity options to fit various setups. The Wi-Fi 6E tri-band radio ensures fast wireless internet access with minimal interference, while Bluetooth 5.3 allows seamless connection to peripherals like keyboards, mice, and headphones. The 2.5 Gb Ethernet port provides a stable wired connection for tasks requiring low latency, such as online gaming or video conferencing.

• Multiple USB ports on the rear panel accommodate fast external storage and peripherals
• Display outputs support high-resolution monitors without needing a dedicated graphics card
• Expansion slots allow installation of additional cards for enhanced audio, networking, or graphics performance

Ideal uses and environments

The ASUS PRIME B840M-A WIFI-CSM is well suited to users building compact yet powerful systems. Gamers will appreciate the dual PCIe 4.0 x16 slots for high-end graphics cards, while content creators benefit from the high-speed DDR5 memory and multiple M.2 storage options. Office professionals and home users can rely on integrated graphics outputs and robust networking features for smooth productivity and media consumption. Its balance of size, performance, and connectivity makes it a strong choice for small form factor builds that do not compromise on expandability.