ASUS Prime B840M-R Micro ATX Motherboard DDR5 PCIe 4.0 AMD AM5

General

SKU	ASP-B84-0MR

Features

Brand	Asus
Model Number	90MB1PT0-M0EAY0
Motherboard Chipset	B840 Chipset (Ryzen AM5)
CPU Socket Type	AM5
Memory Type	DDR5
Outputs	DisplayPort, HDMI
Form Factor	Micro ATX
Key Features	AMD B840 chipset with AM5 socket supporting Ryzen 9000, 8000 and 7000 series desktop processors up to 120W TDP PCIe 4.0 x16 primary slot for full GPU bandwidth alongside a PCIe 3.0 x1 slot for additional expansion Two M.2 slots including a PCIe 4.0 x4 slot from the CPU and a PCIe 3.0 x4 slot from the chipset alongside four SATA 6Gb/s ports Two DDR5 UDIMM slots supporting up to 128GB with speeds up to 7200 MT/s via overclocking with AMD EXPO and ASUS AEMP support Realtek 7.1 Surround Sound HD Audio with audio shielding, premium capacitors and dedicated audio PCB layers for clean sound output Three Addressable RGB Gen 2 headers for full Aura Sync lighting control across compatible peripherals ASUS 5X Protection III including DIGI+ VRM, LANGuard, overvoltage protection and SafeSlot Core+ for long-term reliability Dual onboard graphics outputs via DisplayPort 1.4 and HDMI 2.1 supporting up to 8K 30Hz and 4K 60Hz respectively

ASUS Prime B840M-R AMD AM5 DDR5 PCIe 4.0 1G LAN Micro-ATX Motherboard

The ASUS Prime B840M-R is a compact and reliable AMD AM5 Micro-ATX motherboard ideal for efficient everyday and entry-level builds. Built on the B840 chipset with PCIe 4.0, dual M.2 slots, DDR5 memory up to 7200 MT/s and Realtek 1G LAN, it delivers a solid and dependable platform for any Ryzen 9000, 8000 or 7000 series system.

Processing & Platform

Built on the AMD B840 chipset with an AM5 socket, the Prime B840M-R supports AMD Ryzen 9000, 8000 and 7000 series desktop processors up to 120W TDP. The PCIe 4.0 x16 primary slot delivers full GPU bandwidth, while a PCIe 3.0 x1 slot provides additional expansion flexibility in a compact Micro-ATX form factor.

Memory & Storage

Two DDR5 UDIMM slots support up to 128GB of memory with speeds reaching 7200 MT/s via overclocking with full AMD EXPO and ASUS AEMP profile support. Two M.2 slots and four SATA 6Gb/s ports provide flexible storage options with RAID 0, 1, 5 and 10 support across Ryzen 9000, 8000 and 7000 series processors.

Audio, Protection & Features

The Realtek 7.1 Surround Sound HD Audio codec with audio shielding, premium capacitors and dedicated PCB layers ensures clean and immersive sound output. ASUS 5X Protection III covers DIGI+ VRM, LANGuard, overvoltage protection and SafeSlot Core+ for long-term reliability, while three Addressable RGB Gen 2 headers provide full Aura Sync lighting control throughout your build.

Specifications

CPU AMD Socket AM5 for AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors*
Supports up to AMD 120W CPU
* Refer to https://www.asus.com/support/download-center/ for CPU support list.
Chipset AMD B840 Chipset
Memory "2 x DIMM slots, max. 128GB, DDR5
Supports up to
7200+MT/s(OC) with Ryzen™ 9000 & 7000 Series Processors,
7600+MT/s(OC) with Ryzen™ 8000 Series Processors,
Non-ECC Un-buffered DIMM*"
Dual channel memory architecture
Supports AMD Extended Profiles for Overclocking (EXPO™)
ASUS Enhanced Memory Profile (AEMP)

Graphics

1 x DisplayPort**
1 x HDMI™ port***
* Available only on processors featuring integrated graphics. Graphics specifications may vary between CPU types. Please refer to AMD CPU specifications.
** Supports max. 8K@30Hz as specified in DisplayPort 1.4.
*** Supports 4K@60Hz as specified in HDMI 2.1.

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 x1 slot

Storage

Total supports 2 x M.2 slots and 4 x SATA 6Gb/s ports
AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors
M.2_1 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode)

AMD B840 Chipset

M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 3.0 x4 mode)
4 x SATA 6Gb/s ports
RAID Support AMD RAIDXpert2 Technology
Ryzen™ 9000 & 8000 & 7000 Series Processors: RAID 0/1/5/10
Ethernet 1 x Realtek® 1Gb Ethernet
ASUS LANGuard
USB Rear USB (Total 6 ports)
4 x USB 5Gbps ports (4 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
Front USB (Total 7 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
* USB Type-C® output (USB Type-C Current): max. 5V/3A.
Audio "Realtek® 7.1 Surround Sound High Definition Audio CODEC*
- Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking
- Supports up to 24-Bit/192 kHz playback"
Audio Features
- Audio Shielding
- Premium audio capacitors
- Dedicated audio PCB layers

Back Panel I/O

Ports 4 x USB 5Gbps ports (4 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
1 x DisplayPort
1 x HDMI™ port
1 x Realtek® 1Gb Ethernet port
3 x Audio jacks
1 x PS/2 keyboard/mouse combo port
Internal I/O Connectors Fan and Cooling Related
1 x 4-pin CPU Fan header
2 x 4-pin Chassis Fan headers

Power Related

1 x 24-pin Main Power connector
1 x 8-pin +12V CPU Power connector
Storage Related
2 x M.2 slots (Key M)
4 x SATA 6Gb/s ports

USB

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

Miscellaneous

3 x Addressable RGB Gen 2 headers
1 x Clear CMOS 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 Front Panel System header
Special Features ASUS 5X PROTECTION III
- DIGI+ VRM
- LANGuard
- Overvoltage protection
- SafeSlot Core+
- Stainless-steel back I/O
ASUS Q-Design
- Q-Dashboard
- Q-DIMM
- Q-LED (CPU [red], DRAM [yellow], VGA [white], Boot Device [yellow green])
- Q-Slot
ASUS Thermal Solution
- Aluminum heatsink design
Aura Sync
- Addressable RGB Gen 2 headers
Software Features ASUS Exclusive Software
Armoury Crate
- Aura Creator
- Aura Sync
- Fan Xpert 2+
ASUS DriverHub
- ASUS MB Manager
- ASUS AI Advisor
- ASUS CPU-Z
- TurboV Core
- Norton 360 Deluxe (60 Days Free Trial)
- WinRAR (40 Days Free Trial)
Adobe Creative Cloud (Free Trial)**
UEFI BIOS
AI Cache Boost
ASUS EZ DIY
- ASUS CrashFree BIOS 3
- ASUS EZ Flash
- ASUS UEFI BIOS EZ Mode
- ASUS MyHotkey

Accessories

Cables
2 x SATA 6Gb/s cables
Miscellaneous
1 x I/O shield
1 x Screw package for M.2 SSD
Documentation
1 x Quick start guide
Operating System Windows 11 , Windows 10 64-bit
Form Factor micro-ATX Form Factor
9.3 inch x 9.0 inch (23.6 cm x 22.9 cm)

Dimension

Product (mm)_ L*W*H 236mm*229mm*36.5mm
Color Box (mm)_ L*W*H 260mm*270mm*51.5mm

Weight

Motherboard only 0.563Kg
Full package 0.924Kg