MB ASUS PRIME B860M-A-CSM B860 LGA1851 4XDDR5DC-8400(OC) HDMI 2XDP 1XPCIE5.0X16 4XSATA3 2XM.2 USB MATX 90MB1K00-M0EAYC

CPU
Support Intel® Core™ Ultra Processors (Series 2) , LGA1851
Supports Intel® Turbo Boost Technology 2.0 and Intel® Turbo Boost Max Technology 3.0

Chipset
Intel® B860 Chipset

Memory
4 x DIMM slots, max. 256GB, DDR5
Supports up to 8666+MT/s (OC), Non-ECC,Un-buffered ,Clocked Unbuffered DIMM (CUDIMM)
Dual channel memory architecture
DIMM Fit
Supports Intel® Extreme Memory Profile (XMP) memory module
ASUS Enhanced Memory Profile III(AEMPIII)

Graphics
2 x DisplayPort
1 x HDMI™ port

Expansion Slots
Intel® Core™ Ultra Processors(series 2): 
- 1 x PCIe 5.0 x16 slot
Intel® B860 Chipset: 
- 1 x PCIe 4.0 x16 slot (supports x4 mode)
- 1 x PCIe 4.0 x1 slot

Storage
Total supports 2 x M.2 slots and 4 x SATA 6Gb/s ports
Intel® Core™ Ultra Processors (Series 2) : 
- M.2_1 slot (Key M), type 2242/2260/2280  (supports PCIe 5.0 x4 mode)
Intel®B860 Chipset: 
- M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 modes)
- 4 x SATA 6Gb/s ports

Ethernet
1 x Realtek 2.5Gb Ethernet
ASUS LANGuard

USB
Rear USB (Total 8 ports): 
- 1 x USB 20Gbps port (1 x USB Type-C®)
- 1 x USB 10Gbps port (1 x Type-A )
- 2 x USB 5Gbps ports (2 x Type-A)
- 4 x USB 2.0 ports (4 x Type-A)
Front USB (Total 5 ports): 
- 1 x USB 10Gbps connector (supports USB Type-C® )
- 1 x USB 5Gbps header supports 2 additional USB 5Gbps ports
- 1 x USB 2.0 header supports 2 additional USB 2.0 ports

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

Back Panel I/O Ports
1 x USB 20Gbps port (1 x USB Type-C®)
1 x USB 10Gbps port (1 x Type-A)
2 x USB 5Gbps ports (2 x Type-A)
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

Internal I/O Connectors
Fan and Cooling Related: 
- 1 x 4-pin CPU Fan header
- 1 x 4-pin CPU OPT Fan header
- 1 x 4-pin AIO Pump 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 10Gbps connector (supports USB Type-C® )
- 1 x USB 5Gbps header supports 2 additional USB 5Gbps ports
- 1 x USB 2.0 header supports 2 additionalUSB 2.0 ports
Miscellaneous: 
- 3 x Addressable Gen 2 headers
- 1 x Aura RGB header
- 1 x Clear CMOS header
- 1 x Chassis Intrusion 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 System Panel header
- 1 x Thunderbolt™ (USB4®) header

Special Features
ASUS 5X PROTECTION III: 
- DIGI+ VRM (- Digital power design with DrMOS)
- ESD Guards
- LANGuard
- Overvoltage protection
- SafeSlot
- 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: 
- ProCool
- Pre-mounted I/O shield
Aura Sync: 
- Aura RGB header
- Addressable Gen2 headers

Software Features
ASUS Exclusive Software: 
Armoury Crate
- Aura Creator
- Aura Sync
- Fan Xpert 2+
- Power Saving
ASUS DriverHub
ASUS CPU-Z
Norton 360 for Deluxe (60 Days Free Trial)
WinRAR (40 Days Free Trial)
UEFI BIOS: 
ASUS EZ DIY
- ASUS CrashFree BIOS 3
- ASUS EZ Flash
- ASUS UEFI BIOS EZ Mode
- ASUS MyHotkey

BIOS
256 (128+128) 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
- 1 x Screw package for M.2 SSD
Documentation: 
- 1 x ACC Express Activation Key Card
- 1 x Quick start guide

Operating System
Windows 11 (22H2 & later), Windows 10 64-bit (21H2 & later)

Form Factor
micro-ATX Form Factor
9.6 inch x 9.6 inch (24.4 cm x 24.4 cm)