MotherboardsAsus
ASUS PRIME B840M-A
Quick Specs
ChipsetAMD B840 Chipset
SocketAM5
MemoryDDR5
Form FactormATX
M.2 Slots6
Model: 30829
About this motherboards
Explore the ASUS PRIME B840M-A motherboard, designed for AMD Ryzen™ 9000 series processors, featuring DDR5 support, 2.5Gb Ethernet, and PCIe 4.0.
Technical Specifications23 specs
General
Model
PRIME B840M-A
News Updates
- Please visit our
- GLOBAL website
- to check and download the latest updates.
Cpu
- AMD Socket AM5 for AMD Ryzen
- ™
- 9000 & 8000 & 7000 Series Desktop Processors
- * Refer to
- https://www.asus.com/support/download-center/
- for CPU support list.
Chipset
AMD B840 Chipset
Memory
- 4 x DIMM slots, max. 256GB, DDR5
- Supports up to 7600+MT/s (OC) with Ryzen
- ™
- 9000 & 8000 & 7000 Series Processors, ECC and Non-ECC, Un-buffered DIMM
- Dual channel memory architecture
- 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 site or visit
- https://www.asus.com/support/download-center/
- . 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.
Graphics
- 2 x DisplayPort
- 1 x HDMI
- ™
- port
- * 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
- 2 x PCIe 3.0 x16 slots (support x1 mode)
- * Please check the PCIe bifurcation table on the support site (
- https://www.asus.com/support/FAQ/ 1037507/
- ).
- ** Specifications vary by CPU types.
- - To ensure compatibility of the device installed, please refer to
- https://www.asus.com/support/download-center/
- for the list of supported peripherals.
Storage
- Total supports 3 x M.2 slots and 4 x SATA 6Gb/s ports
- AMD Ryzen
- ™
- 9000 & 7000 Series Desktop Processors
- M.2_1 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode)
- M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode)
- AMD Ryzen
- ™
- 8000 Series Desktop Processors
- M.2_1 slot (Key M), type 2280 (supports PCIe 4.0 x4 mode)
- M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4/x2 mode)
- AMD B840 Chipset
- M.2_3 slot (Key M), type 2280 (supports PCIe 3.0 x4 mode)
- 4 x SATA 6Gb/s ports
- * Specifications vary by CPU types.
- AMD RAIDXpert2 Technology
- Ryzen
- ™
- 9000 Series Processors: RAID 0/1/5/10
- Ryzen
- ™
- 8000 Series Processors: RAID 0/1
- Ryzen
- ™
- 7000 Series Processors: RAID 0/1/10
Ethernet
- 1 x Realtek 2.5Gb Ethernet
- ASUS LANGuard
Usb
- Rear USB (Total 7 ports)
- 2 x USB 10Gbps ports (2 x Type-A)
- 1 x USB 5Gbps port (1 x USB Type-C
- ®
- )
- 4 x USB 2.0 ports (4 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
- ®
- power delivery output: 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
- * A chassis with an HD audio module in the front panel is required to support 7.1 Surround Sound audio output.
Back Panel I O Ports
- 2 x USB 10Gbps ports (2 x Type-A)
- 1 x USB 5Gbps port (1 x USB Type-C
- ®
- )
- 4 x USB 2.0 ports (4 x Type-A)
- 2 x DisplayPort
- 1 x HDMI
- ™
- port
- 1 x Realtek 2.5Gb Ethernet port
- 3 x Audio jacks
- 1 x BIOS FlashBack
- ™
- button
Internal I O
- Fan and Cooling Related
- 1 x 4-pin CPU Fan header
- 1 x 4-pin CPU OPT 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
- 3 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 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 Core
- - Q-Slot
- ASUS Thermal Solution
- - M.2 heatsink
- - VRM heatsink design
- ASUS EZ DIY
- - BIOS FlashBack™ button
- - BIOS FlashBack™ LED
- - Pre-mounted I/O shield
- Aura Sync
- - Addressable Gen 2 headers
Software Features
- ASUS Exclusive Software
- Armoury Crate
- - Aura Creator
- - Aura Sync
- - Fan Xpert 2+
- - Power Saving
- ASUS DriverHub
- TurboV Core
- ASUS CPU-Z
- Adobe Creative Cloud (Free Trial)
- Norton 360 Deluxe (60 Days Free Trial)
- WinRAR (40 Days Free Trial)
- UEFI BIOS
- ASUS EZ DIY
- - ASUS CrashFree BIOS 3
- - ASUS EZ Flash 3
- - ASUS UEFI BIOS EZ Mode
- - ASUS MyHotkey
Bios
256 Mb Flash ROM, UEFI AMI BIOS
Manageability
WOL by PME, PXE
Accessories
- Cables
- 2 x SATA 6Gb/s cables
- Miscellaneous
- 1 x M.2 rubber package
- 2 x Screw packages for M.2 SSD
- Documentation
- 1 x Quick start guide
Operating System
Windows 11, Windows 10 64-bit
Form Factor
- micro-ATX Form Factor
- 9.6 inch x 9.6 inch (24.4 cm x 24.4 cm)
Physical Dimensions
Length Mm
243.8
Width Mm
243.8
Height Mm
619.8
