ASUS ROG STRIX B860-I GAMING WIFI90MB1JB0-M0AAY0 · LGA1851 · Mini-ITX · ASUS global specification- Form factor
- Mini-ITX: 170 × 170 mmThis one: Micro-ATX; 244 × 222 mm
MOTHERBOARDS
ASUS PRIME B860M-K
LGA1851 · Micro-ATX
- CPU socket
- LGA1851
- Chipset
- Intel B860
- Form factor
- Micro-ATX; 244 × 222 mm
A compact Micro-ATX Intel B860 board for Core Ultra (Series 2) processors with two DDR5 slots, a PCIe 4.0 x16 graphics slot, one PCIe 5.0 x4 and one PCIe 4.0 x4 M.2 slot, four SATA ports and Realtek 2.5 Gb Ethernet.
Prices & buying options
As an Amazon Associate I earn from qualifying purchases.
Price alert
Email me when the ASUS PRIME B860M-K gets cheaper on eBay. We check exact-model listings once a day at 12:00 UTC.
THE ACTUAL PRODUCT
Compare with ASUS ROG STRIX B860-I GAMING WIFI
Specifications checked 26 Sept 2026Manufacturer specifications, not a hands-on test.
The nearest checked motherboards by key specifications, with what differs from the ASUS PRIME B860M-K. The first matches the Compare button above.
ASUS ROG STRIX B860-I GAMING WIFI90MB1JB0-M0AAY0 · LGA1851 · Mini-ITX · ASUS global specification
ASUS ROG STRIX Z890-I GAMING WIFI90MB1IC0-M0AAY0 · LGA1851 · Mini-ITX · ASUS global specification- Chipset
- Intel Z890This one: Intel B860
- Form factor
- Mini-ITX: 170 × 170 mmThis one: Micro-ATX; 244 × 222 mm
ASUS ROG MAXIMUS Z890 APEX90MB1IP0-M0AAY0 · LGA1851 · ATX · ASUS global specification- Chipset
- Intel Z890This one: Intel B860
- Form factor
- ATX: 305 × 244 mmThis one: Micro-ATX; 244 × 222 mm
Key strengths
A PCIe 5.0 x4 M.2 slot plus a second PCIe 4.0 x4 M.2 slot and four SATA ports give several storage options for a small board.
Rated for DDR5 up to 8800+ MT/s (OC) with CUDIMM support, plus 2.5 Gb wired Ethernet and a front USB Type-C connector.
Before you buy
Only two DIMM slots (128 GB maximum), so a later capacity upgrade may mean replacing both modules.
The graphics slot is PCIe 4.0 rather than PCIe 5.0, there is no rear USB-C port and ASUS lists no Wi-Fi.
Works with
Products in this catalogue that list the same socket or memory type as the ASUS PRIME B860M-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.
Start a build with thisOpens My setups with the ASUS PRIME B860M-K in place and checks each part you addEvery specification. With its source.
Full specifications
Exact configuration: PRIME B860M-K · LGA1851 · Micro-ATX · ASUS global specification
26 specifications in 9 groups. Values are manufacturer specifications unless a row says “Measured result” or “Calculated from cited specifications”. 1 row repeats a listed fact in the manufacturer’s own wording, kept under “Manufacturer wording”.
Platform & board
4 items
- CPU socket
- LGA1851Source
- Chipset
- Intel B860Source
- Form factor
- Micro-ATX; 244 × 222 mm
Check case mounting positions and connector clearance.
Source - Specification market
- ASUS global documentation
UK and US buying links are searches, not proof of stock, identical regional bundles or warranty. Confirm the exact model with the retailer.
Source
Memory
4 items
- DIMM slots
- 2
Physical DDR5 module positions; this count is not a guarantee of capacity or profile speed.
Source - Maximum listed memory
- 128 GB
Manufacturer capacity ceiling; check CPU support, BIOS and the validated DIMM population.
Source - Memory type, slots and limit
- 2 DDR5 DIMM slots; dual channel; up to 128 GB; up to DDR5-8800+ (OC); Intel XMP; non-ECC unbuffered; CUDIMM support
ASUS also lists DIMM Fit and ASUS Enhanced Memory Profile III (AEMPIII). · Supported memory types, data rate and module count vary with the CPU and memory configuration (ASUS CPU/Memory support list). Profile support does not guarantee an overclock.
Source - Listed maximum memory speed (OC)
- Up to 8800+ MT/s (OC)
Manufacturer-listed overclocking ceiling, not a guaranteed stock transfer rate or tested performance. CPU, BIOS and DIMM layout remain material.
Source
Expansion slots
1 item
- Expansion slots and electrical links
- 1 × PCIe 4.0 x16; 2 × PCIe 4.0 x1
The PCIe 4.0 x16 slot connects to the CPU; the two PCIe 4.0 x1 slots connect to the B860 chipset. The graphics slot is PCIe 4.0, not PCIe 5.0. · Electrical link widths, not measured performance; see the ASUS supported-peripheral list.
Source
Storage
5 items
- M.2 storage positions
- 2
M.2_1 supports PCIe 5.0 x4 and M.2_2 supports PCIe 4.0 x4. ASUS lists no SATA mode for either M.2 slot.
Source - SATA storage ports
- 4
SATA 6 Gb/s; check the manual for drive power and any lane sharing.
Source - Storage interfaces
- 1 × M.2 PCIe 5.0 x4; 1 × M.2 PCIe 4.0 x4; 4 × SATA 6 Gb/s
M.2_1 connects to the CPU; M.2_2 and the SATA ports connect to the B860 chipset. · Both M.2 slots accept 2242/2260/2280 drives. Intel RAID is listed for SATA drives.
Source - SATA RAID modes
- RAID 0/1/5/10
Intel Rapid Storage Technology; check the manual and BIOS configuration before building an array.
Source - NVMe RAID modes
- Not listed by the manufacturer
ASUS lists Intel RAID modes for SATA drives only; NVMe RAID support is not stated. · Check the manual or BIOS documentation before relying on NVMe arrays.
Source
USB & rear connections
4 items
- Rear connections
- 1 × USB 10 Gb/s (Type-A); 2 × USB 5 Gb/s (Type-A); 3 × USB 2.0 (Type-A); 1 × DisplayPort; 1 × HDMI; Realtek 2.5 Gb Ethernet; 3 audio jacks; 1 × PS/2 keyboard/mouse combo
Rear port inventory only; display output depends on the processor. No rear USB-C port is listed.
Source - Internal USB connections
- 1 × USB 5 Gb/s (Type-C connector); 2 × USB 5 Gb/s (1 header); 4 × USB 2.0 (2 headers)
Headers need compatible case ports or accessories; they are not additional rear sockets. The front USB Type-C connector provides up to 5 V / 3 A.
Source - Integrated-graphics display connections
- DisplayPort 1.4 (up to 4K 60 Hz); HDMI 2.1 (4K 60 Hz)
Requires a processor with integrated graphics; ASUS states graphics specifications vary between CPU types.
Source - Rear USB4 support
- No
The complete rear-panel list tops out at one USB 10 Gb/s Type-A port; no USB4, Thunderbolt or USB-C port is listed.
Source
Networking
2 items
- Network interfaces
- Realtek 2.5 Gb Ethernet
ASUS lists Ethernet only; the Wireless & Bluetooth section of the specification is empty.
Source - Included Wi-Fi
- Not listed by the manufacturer
The Wireless & Bluetooth section of the ASUS specification is empty and the back-panel list has no Wi-Fi module. An omitted specification is not treated as verified absence, so included Wi-Fi remains unknown.
Source
Manufacturer wording (1)
The same facts in the manufacturer’s combined or original wording, each with its source.
- Wired Ethernet
- Realtek 2.5 Gb Ethernet
Link-rate capability; real throughput depends on the connected network, cabling and workload.
Source
Audio
1 item
- Audio hardware
- Realtek 7.1-channel HD audio codec
ASUS does not name the codec model on this page. · 7.1 output needs a chassis with a front-panel HD audio module. A codec description is not a sound-quality measurement.
Source
Power, cooling & lighting
1 item
- Motherboard power connections
- 1 × 24-pin ATX main; 1 × 8-pin +12 V CPU
Check the PSU cable set; graphics-card power is separate.
Source
BIOS, software & diagnostics
4 items
- CPU support / BIOS source
- Intel Core Ultra (Series 2)
Check ASUS's exact CPU support list and its required BIOS. Family support does not confirm the firmware installed on a retail board.
Source - Firmware storage
- 256 (128+128) Mb Flash ROM, UEFI AMI BIOS
Flash-ROM capacity does not identify the BIOS version installed on a retail board.
Source - Listed operating systems
- Windows 11 (22H2 & later); Windows 10 64-bit (21H2 & later)
ASUS's update note: Core Ultra 200S Plus processors need Windows 11 25H2 or later for full compatibility.
Source - BIOS flash button
- Not listed by the manufacturer
The back-panel list names no BIOS FlashBack button and the software list names ASUS EZ Flash and CrashFree BIOS 3 only. A missing listing is not treated as proof of absence.
Source
Compare with another motherboard
More of the nearest checked motherboards by key specifications, for a side-by-side comparison.
ASUS PRIME B860-PLUS WIFIPRIME B860-PLUS WIFI · LGA1851 · ATX · ASUS global specificationCompare the two 
ASUS PRIME B860M-A WIFIPRIME B860M-A WIFI · LGA1851 · Micro-ATX · ASUS global specificationCompare the two 
ASUS PRIME B860M-APRIME B860M-A · LGA1851 · Micro-ATX · ASUS global specificationCompare the two 
MSI PRO B860-P WIFILGA 1851 · DDR5 · ATX · MSI global specificationCompare the two 
MSI MAG B860 TOMAHAWK WIFILGA 1851 · DDR5 · ATX · MSI global specificationCompare the two 
ASUS TUF GAMING B860-PLUS WIFITUF GAMING B860-PLUS WIFI · LGA1851 · ATX · ASUS global specificationCompare the two 
ASUS TUF GAMING B860M-PLUS WIFITUF GAMING B860M-PLUS WIFI · LGA1851 · Micro-ATX · ASUS global specificationCompare the two 
ASUS TUF GAMING B860M-PLUSTUF GAMING B860M-PLUS · LGA1851 · Micro-ATX · ASUS global specificationCompare the two