ASUS Prime B840-Plus WIFI-CSM ATX Motherboard
MPN PRIME-B840-PLUS-WIFI-CSM · Brand ASUS · ATX
The ASUS Prime B840-Plus WIFI-CSM is an ATX motherboard for AMD AM5 processors (Ryzen 9000/8000/7000) featuring DDR5 support up to 7600+, WiFi 6E, three M.2 slots, and a Realtek 2.5 Gb LAN port
Inclusive of GST · GST invoice available
Overview
The ASUS Prime B840-Plus WIFI-CSM is a full-sized ATX motherboard built around the AMD B840 chipset and the AM5 socket, making it compatible with AMD Ryzen 9000, Ryzen 8000, and Ryzen 7000 series desktop processors. Designed with both PC builders and system integrators in mind, it balances accessible pricing with a thoughtfully specified feature set that covers everyday computing, content creation, and AI-ready workloads. Power delivery is handled by an 8+2+1 phase digital power design using discrete MOSFETs. This configuration is engineered to provide stable voltage to the CPU under sustained loads, contributing to consistent day-to-day performance. The board ships with a single 8-pin and a supplementary 4-pin +12V CPU power connector, giving builders flexibility for their PSU cable configurations. Memory support is built around DDR5, with the board accepting up to 256 GB across dual-channel slots. Speeds are listed as reaching DDR5-7600+ through EXPO (AMD Extended Profiles for Overclocking) profiles, and ASUS's own AEMP (ASUS Enhanced Memory Profile) technology helps extract optimised performance even from entry-level DDR5 kits that lack EXPO certification. Non-ECC, unbuffered modules with Die ECC support are also accommodated. Storage is covered by three M.2 Key-M slots: two operating via PCIe 4.0 at up to 64 Gbps each, and one via PCIe 3.0. Four SATA 6 Gb/s ports add capacity for additional drives. On the expansion side, Ryzen 9000 and 7000 processors unlock a full PCIe 4.0 x16 slot running at x16 mode for discrete graphics, while Ryzen 8000 series processors run it at x8/x4. The B840 chipset contributes additional PCIe 3.0 slots. Connectivity is a strong point. Built-in WiFi 6E and Bluetooth 5.3 handle wireless networking, while a Realtek 2.5 Gb Ethernet port serves wired connections. The rear I/O panel includes a USB Type-C port and a Type-A port both running at 10 Gbps, two USB 5 Gbps Type-A ports, four USB 2.0 Type-A ports, DisplayPort, HDMI, three audio jacks, and a BIOS FlashBack button for firmware updates without a CPU installed. Internally, a Thunderbolt (USB4) header, three Addressable Gen 2 (ARGB) headers, an AIO pump header, and four chassis fan headers provide builders with extensive system-building flexibility. The board carries a 3-year manufacturer warranty. Key Verified Specifications: - Socket: AM5 - Chipset: AMD B840 - Compatible CPUs: AMD Ryzen 9000, 8000, 7000 series desktop processors - Form Factor: ATX - Memory: DDR5, Dual Channel, up to 256 GB, up to DDR5-7600+ (EXPO/AEMP) - Storage: 3x M.2 (Key M) – 2x PCIe 4.0 up to 64 Gbps, 1x PCIe 3.0; 4x SATA 6 Gb/s - Wireless: WiFi 6E, Bluetooth 5.3 - LAN: Realtek 2.5 Gb Ethernet - Rear USB: 1x USB-C 10 Gbps, 1x Type-A 10 Gbps, 2x Type-A 5 Gbps, 4x USB 2.0 - Display Output: 1x DisplayPort, 1x HDMI - Power Design: 8+2+1 phase with discrete MOSFETs - Warranty: 3 Years
Datasheet
| Memory Type | DDR5 |
|---|---|
| Warranty | 3 Years |
| Form Factor | ATX |
| Chipset | B840 |
| Socket | AM5 |
| CPU Type | Ryzen 9000,Ryzen 8000,Ryzen 7000 |
| Max Memory | 256 GB |
| Memory Speed | up to 7600+ |
| Platform | AMD |
| Graphics Port | 1 x DisplayPort,1 x HDMI |
| Memory Feature | 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, for more information please refer to CPU/Memory Support list under the Support tab of product information visit on Brand Site. Adjustments will be made based on the specifications of mass-produced memory products available on the market. * Non-ECC, un-buffered DDR5 memory supports On-Die ECC function |
| 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 1 x PCIe 3.0 x16 slot (support x4 mode)*** 2 x PCIe 3.0 x16 slots (support x1 mode)*** 1 x PCIe 3.0 x1 slot*** * Please check the PCIe bifurcation table on the support site. ** Specifications vary by CPU types. *** The PCIEX16(G3)_1/3 and PCIEX1(G3) share bandwidth with PCIEX16(G3)_2. The PCIEX16(G3)_2 will run x1 mode when any of the PCIEX16(G3)_1/3 and PCIEX1(G3) slots is occupied |
| Channel Supported | Dual Channel |
| Wireless Networking | WiFi 6E,Bluetooth 5.3 |
| Back Panel I/O Ports | 1 x USB 10Gbps port (1 x USB Type-C®) 1 x USB 10Gbps port (1 x Type-A) 2 x USB 5Gbps ports (2 x Type-A) 4 x USB 2.0 ports (4 x Type-A) 1 x DisplayPort 1 x HDMI™ port 1 x Wi-Fi module 1 x Realtek 2.5Gb Ethernet port 3 x Audio jacks 1 x BIOS FlashBack™ button |
| Internal I/O Connector | 1 x 4-pin CPU Fan header 1 x 4-pin CPU OPT Fan header 1 x 4-pin AIO Pump header 4 x 4-pin Chassis Fan header 1 x 24-pin Main Power connector 1 x 8-pin +12V CPU Power connectors 1 x 4-pin +12V CPU Power connectors 3 x M.2 slots (Key M) 4 x SATA 6Gb/s 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 3 x Addressable Gen 2 headers 1 x Clear CMOS header 1 x Chassis Intrusion header 1 x COM Port header 1 x Front Panel Audio header (F_AUDIO) 1 x S/PDIF Out header 1 x SPI TPM header (14-1 pin) 1 x 10-1 pin System Panel header 1 x Thunderbolt™ (USB4®) header |
