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

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

MPN: 90MB1J10-M0EAYC

Key specifications

SocketAM5
Form factormATX
ChipsetAMD B840
Memory typeDDR5
M.2 slots3
Max Memory192 GB
Best indexed price
£138.97GBP
Indexed 20 Oct 2026 — verify at retailer. How we get prices

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Scan£138.97
Indexed 20 Oct 2026New
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eBay UK£145.15
Indexed 16 Mar 2026New · seller youritdelivered
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Full Specifications77 fields

Additional Information

Model Number
90MB1J10-M0EAYC
Gtin
4711387797204

Additional Specifications

Water Cooled
No
Cooling
Passive Heatsinks
Qpi Speed
N/A
Dimensions
244x244x50mm ( L x W x H) mm
Note
-

Back Connect

Back Connect
No

Colour

Primary Colour
Black

Cooling

Backplate
Yes
M 2 Heatsinks
Yes
Vrm Heatsinks
Yes

Core Specifications

Edition
PRIME B840M-A
Form Factor
MicroATX
Chipset
AMD B840

CPU

Cpu Manufacturer
AMD
Socket
AM5

Dimensions

Length Depth
244 mm
Width
244 mm

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

External Connectivity

Network Interface Type
Wired 2.5 Gigabit LAN
Network Chip Modules
1 x Realtek (2.5GbE LAN)
Rear I O Connectors
1 x 10/100/1000/2500 (LAN) 1 x BIOS Flashback Button 2 x DisplayPort 1 x HDMI 1 x Line In 1 x Line Out 1 x Mic-In 4 x USB 2.0 1 x USB 3.1 Gen1 Type-C 2 x USB 3.2

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)

Fan Header

4 Pin Fan Connectors
6

Form Factor

Motherboard Formfactor
Micro-ATX

Graphics Support

Primary Gpu Interface
PCIe 4.0 (x16)
Nvidia Sli Support
N/A
Amd Crossfire Support
N/A
Integrated Graphics
-
On Board Graphics Connectors
None

Internal Connectivity

Expansion Slots
1 x M.2, 22-42/60/80, PCIe Gen4x4 1 x M.2, 22-80, PCIe Gen3 1 x M.2, 22-80, PCIe Gen4x4 2 x PCIe 3.0 x16 1 x PCIe 4.0 x16
Sata Support
N/A
Raid Support Via
-
Storage Mode Support
RAID 0 RAID 1 RAID 10 RAID 5
Internal I O
1 x 24-pin (Power) 2 x 4-pin CHA_FAN connector 1 x 4-pin CPU Fan Connector 1 x 4-pin CPU OPT Fan Connector 1 x 8-pin (Power) 3 x Addressable Gen 2 Header 1 x Clear CMOS Header 1 x Front Panel Audio Header 1 x Front Panel Connector 1 x S/PDIF-Out Header 4 x SATA III - 6Gb/s 1 x Serial (COM) Header 1 x TPM (SPI_TPM) header

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

Lighting

Lighting Rgb
Yes

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

Motherboard

Motherboard Chipset
AMD B840
Built In I O Shield
Yes

RAM Memory Support

Memory Channel
-
Memory Type Ecc
ECC/Non-ECC
Memory Type R U
UDIMM (Unbuffered)
Memory Speed Mhz
DDR5 - 7600(OC)
Max Memory Capacity
192GB (4x48GB)

Storage Ports

M 2 Pcie 3 0 X4
1
M 2 Pcie 4 0 X4
2
Sata 6g Internal
4

Wi

Fi Lan Lan
Yes
Fi Lan Lan Ports
1x 2.5 Gbit/s
Fi Lan Wi Fi Bluetooth
No

General

Audio
7.1 Channel HD Audio