ASUS B850M-E AYW GAMING WIFIUK manufacturer specification · B850M-E AYW GAMING WIFI- Chipset
- AMD B850 ChipsetThis one: AMD B840 Chipset
MOTHERBOARDS
ASUS PRIME B840M-K
UK manufacturer specification
- CPU socket
- AM5
- Chipset
- AMD B840 Chipset
- Form factor and dimensions
- micro-ATX Form Factor 9.6 inch x 8.7 inch ( 24.4 cm x 22.1 cm )
PRIME B840M-K motherboard, identified in the ASUS UK catalogue. Specifications below retain the manufacturer’s configuration and interface conditions.
Prices & buying options
As an Amazon Associate I earn from qualifying purchases.
Price alert
Email me when the ASUS PRIME B840M-K gets cheaper on eBay. We check exact-model listings once a day at 12:00 UTC.
THE ACTUAL PRODUCT
Compare with ASUS B850M-E AYW GAMING WIFI
Specifications checked 17 Oct 2026Manufacturer specifications, not a hands-on test.
The nearest checked motherboards by key specifications, with what differs from the ASUS PRIME B840M-K. The first matches the Compare button above.
ASUS B850M-E AYW GAMING WIFIUK manufacturer specification · B850M-E AYW GAMING WIFI
ASUS EX-B850M-V7-CSMUK manufacturer specification · EX-B850M-V7-CSM- Chipset
- AMD B850 ChipsetThis one: AMD B840 Chipset
ASUS EX-B850M-V7UK manufacturer specification · EX-B850M-V7- Chipset
- AMD B850 ChipsetThis one: AMD B840 Chipset
Key strengths
Published motherboard interfaces and configuration are available from the exact-model ASUS specification source.
Before you buy
Compatibility and maximum operating modes depend on the source’s stated hardware, firmware and connection requirements; manufacturer figures are not independent measurements.
Works with
Products in this catalogue that list the same socket or memory type as the ASUS PRIME B840M-K. A shared socket or memory type is necessary but not sufficient: check the exact CPU and memory support lists, and the BIOS version, before buying.
- 19 AM5 processorsSocket AM5 on both, from cited specifications
- 50 DDR5 memory kitsMemory type DDR5 on both, from cited specifications
Every specification. With its source.
Full specifications
Exact configuration: UK manufacturer specification · PRIME B840M-K
13 specifications in 9 groups. Values are manufacturer specifications unless a row says “Measured result” or “Calculated from cited specifications”.
Platform & board
3 items
Memory
1 item
- Memory type, slots and limit
- 2 x DIMM slots, max. 128GB, DDR5 Supports up to 8000+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) * Max Manual Overclocking: Achievable with advanced BIOS configuration and potentially specialized hardware. Results may vary according to system components. * XMP/EXPO/AEMP Profiles: Rated memory module speeds require a BIOS performance profile setting. Results may vary according to system components and can be impacted when four DIMM slots are used. * 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.Source
Expansion slots
1 item
- Expansion slots and restrictions
- 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 x16 slot (supports x4 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.Source
Storage
1 item
- Storage interfaces and restrictions
- Total supports 2 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 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 2280 (supports PCIe 4.0 x4/x2 mode)* AMD B840 Chipset 4 x SATA 6Gb/s ports * Specifications vary by CPU types.Source
USB & rear connections
2 items
- USB ports and headers
- 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® power delivery output: max. 5V/3A.Source
- Rear-panel ports
- 4 x USB 5Gbps ports (4 x Type-A) 2 x USB 2.0 ports (2 x Type-A) 1 x HDMI™ port 1 x Realtek® 2.5Gb Ethernet port 3 x Audio jacksSource
Networking
1 item
- Network interfaces and requirements
- 1 x Realtek® 2.5Gb Ethernet ASUS LANGuardSource
Audio
1 item
- Audio interfaces
- 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.Source
Power, cooling & lighting
1 item
- Internal headers and connectors
- Fan and Cooling Related 1 x 4-pin CPU Fan header 3 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 headerSource
BIOS, software & diagnostics
2 items
- CPU support and BIOS requirements
- AMD Socket AM5 for AMD Ryzen™ 9000 & 8000 & 7000 Series Desktop Processors* Supports up to AMD 170W CPU * Refer to https://www.asus.com/support/download-center/ for CPU support list. BIOS: 32MB (256Mb) Flash ROM, UEFI AMI BIOS
Exact CPU support and BIOS revision depend on the processor and the current ASUS CPU support list; the family statement is not a guarantee for every processor.
Source - Listed operating systems
- Windows 11, Windows 10 64-bitSource
Compare with another motherboard
More of the nearest checked motherboards by key specifications, for a side-by-side comparison.
ASUS B840M AYW GAMING WIFIUK manufacturer specification · B840M AYW GAMING WIFICompare the two 
ASUS PRIME B840M-K-CSMUK manufacturer specification · PRIME B840M-K-CSMCompare the two 
ASUS PRIME B650M-KUK manufacturer specification · PRIME B650M-KCompare the two 
ASUS PRIME B850M-K-CSMUK manufacturer specification · PRIME B850M-K-CSMCompare the two 
ASUS PRIME B850M-KUK manufacturer specification · PRIME B850M-KCompare the two 
ASUS B850M-E AYW GAMING WIFI-CSMGlobal manufacturer specification · B850M-E AYW GAMING WIFI-CSMCompare the two 
ASUS B850M AYW GAMING WIFI-CSMGlobal manufacturer specification · B850M AYW GAMING WIFI-CSMCompare the two 
ASUS B850M AYW GAMING WIFIGlobal manufacturer specification · B850M AYW GAMING WIFICompare the two