ASUS PRIME B840M-A-CSM AMD B840 Ryzen Socket AM5 Micro-ATX Desktop Motherboard
R2 221
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ASUS · 285 products
Overview
- Micro-ATX Form Factor
- AMD B840 Chipset
- Socket AM5
- 4x DDR5 DIMM Slots, Supports Up To 192GB
- Supports Up to DDR5-7600MHz+ (OC)
- Supports AMD EXPO DDR5 Modules
- 1x PCIe 4.0 x16 slot (supports x16 mode),
- 2x PCIe 3.0 x16 slots (support x1 mode)
- Total supports 3 x M.2 slots and 4 x SATA 6Gb/s ports
- 2x USB 10Gbps Type-A Ports, 1x USB 5Gbps Type-C Port
- 4x USB 2.0 Type-A Ports, 2x DisplayPort, 1x HDMI Port
- 1x Realtek 2.5Gb Ethernet Port, 3x Audio Jacks
- 1x BIOS FlashBack Button
- Realtek 2.5Gb Ethernet
- Realtek 7.1 Surround Sound High Definition Audio CODEC
- ASUS 5X PROTECTION III
- ASUS Q-Design
- ASUS Thermal Solution
- ASUS EZ DIY BIOS FlashBack LED & Button
- ASUS Aura Sync
- 3 Year Warranty
Specifications
SPECIFICATIONS
- ASUS
- AMD B840 Series
- PRIME B840M-A-CSM
- 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.
- AMD B840 Chipset
- 4 x DIMM slots, max. 192GB, 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.
- 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.
- 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.
- 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
- 1 x Realtek 2.5Gb Ethernet
- ASUS LANGuard
- 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
- 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.
- 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
- 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
- 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
- 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
- IT Management software supported
- ASUS Control Center Express (ACCE)
- 256 Mb Flash ROM
- UEFI AMI BIOS
- WOL by PME, PXE
- 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 ACC Express Activation Key Card
- 1 x Quick start guide
- Windows 11, Windows 10 64-bit
- micro-ATX Form Factor
- 9.6 inch x 9.6 inch (24.4 cm x 24.4 cm)
Additional information
- No
- No
Customer reviews
5.0 Based on 1 review
- 5.0Bergvliet High School
A good solid no frills motherboard
This motherboard is great for a school or office type computer that is expected to have a long service life. It's a basic board without many frills, keeping the cost low, but because it's a CSM part, it's supposed to be available and supported longer than the more commercial models for home/gamer use. Feature wise, this board has more than enough I/O for typical school/office use. It could do with a few more USB3 ports on the back, but that aside it's more than good enough for most lower cost use cases. About the only other thing I can think of that would be good on these types of boards is something like Intel's v-Pro remote management stuff, but I don't think AMD have really played much in that space yet. Otherwise, combined with the well-behaved ASUS UEFI, you have a good solid board that will behave well for years to come.
- Product Rating5/5
Questions & answers
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