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Asus PRIME B840M-A-CSM (Socket AM5) DDR5 Micro-ATX Motherboard

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Socket AM5, B840 Chipset, Supports 7000/8000/9000 series AMD Ryzen, 4x DIMM Slots, DDR5 7600MHz (OC), PCIe Gen 4, 4x SATA 6Gb/s connectors, 3x M.2 Slot, 2.5GB LAN, mATX
£175.99 (incl. VAT)
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SKU MOT-ASU-03850
EAN 4711387797204
MPN 90MB1J10-M0EAYC
MANUFACTURER Asus
Specification Details
CPU AMD Socket AM5 for AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors*
* Refer to ASUS Support for CPU support list.
Chipset AMD B840 Chipset
Memory 4 x DIMM slots, max. 192GB, DDR5
Support 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 ASUS Support. 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 (ASUS FAQ).
** Specifications vary by CPU types.
- To ensure compatibility of the device installed, please refer to ASUS Support 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 Connectors 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)
Lighting
Lighting Yes
Back Connect
Back Connect No
Form Factor
Motherboard formfactor Micro-ATX
Colour
Primary Colour Black
Motherboard
Motherboard Chipset AMD B840
Built-In I/O Shield Yes
CPU
CPU Manufacturer AMD
CPU Socket AM5
Dimensions
Length / Depth 244 mm
Width 244 mm
Wi-Fi & LAN
LAN Yes
LAN Ports 1x 2.5 Gbit/s
Wi-Fi / Bluetooth No
Memory
Max. Memory 192 GB
Memory Type DDR5
Memory Form Factor DIMM
Max. Memory Speed (OC) 7600 MT/s
EEC Support Yes
Memory slots 4x
Performance Profile AMD EXPO
Fan Header
4 Pin Fan Connectors 6
Expansion Slots
PCIe x16 slots (total) 1
PCIe x1 slots (total) 2
PCIe 4.0 x16 mechanical slot 1
PCIe 3.0 x16 mechanical slot 2
Internal Ports
CPU Power Supply 1x 8-Pin
USB 3.0 / 3.1 / 3.2 (internal) Type C Header 1
USB 3.0 / 3.1 / 3.2 (internal) Type C Possible Ports 1
USB 3.0 (internal) Header 1
USB 3.0 (internal) Possible Ports 2
USB 2.0 (internal) Header 2
USB 2.0 (internal) Possible Ports 4
RGB / LED connectors 3x Digital RGB (3-Pin 5VDG)
Front Panel Audio Header Yes
SPI TPM Header Yes
External Ports
USB 3.1 (external) Type A 2
USB 3.0 (external) Type C 1
USB 2.0 (external) Type A 4
Display Connectors HDMI (1x), Display Port (2x)
Storage Ports
M.2 PCIe 3.0 x4 1
M.2 PCIe 4.0 x4 2
SATA 6G (internal) 4
Cooling
Backplate Yes
M.2 Heatsinks Yes
VRM Heatsinks Yes
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£175.99 (incl. VAT)
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