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ASRock B850M Pro RS AMD AM5 Socket Motherboard, Micro-ATX, 4x DDR5 Slots, 3x M.2 Sockets, Fitted I/O Shield, 2.5GbE LAN, 1x DisplayPort / 1x HDMI Port

ASRock B850M Pro RS AMD AM5 Socket Motherboard, Micro-ATX, 4x DDR5 Slots, 3x M.2 Sockets, Fitted I/O Shield, 2.5GbE LAN, 1x DisplayPort / 1x HDMI Port

Regular price £128.99 GBP
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ASRock B850M PRO RS Micro ATX Motherboard (AMD B850, AM5)

The ASRock B850M PRO RS is a Micro ATX motherboard designed for AMD Socket AM5 Ryzen 9000, 8000, and 7000 Series processors, delivering a solid balance of performance, connectivity, and durability for modern gaming and productivity builds.


Key Features

  • CPU Support
  • Supports AMD Socket AM5 Ryzen 9000, 8000 and 7000 Series Processors
  • AMD B850 chipset

  • Power Design

  • 8 + 2 + 1 power phase design
  • Dr.MOS for VCore + SOC + MISC
  • VCore with Dr.MOS design for smoother and neater CPU power delivery

  • Memory

  • 4 x DDR5 DIMM slots
  • Dual Channel DDR5 memory technology
  • Supports DDR5 ECC/non-ECC, un-buffered memory up to 8000+ (OC)
  • Max system memory capacity: 256GB
  • Supports XMP and EXPO memory profiles

  • Graphics & Display

  • Integrated AMD RDNA graphics (support varies by CPU)
  • 1 x HDMI 2.1 TMDS/FRL 8G compatible, HDR, HDCP 2.3, up to 4K 120Hz
  • 1 x DisplayPort 1.4 with DSC, HDCP 2.3, up to 4K 120Hz

  • Expansion & Slots

  • 1 x PCIe 5.0 x16 slot (PCIE1), supports x16 mode
  • 1 x PCIe 4.0 x4 slot (PCIE2), supports x4 mode
  • 1 x M.2 Key E slot (type 2230) for WiFi/BT PCIe wireless module
  • PCIE1 behavior:
    • Gen5 x16 with Ryzen 9000 & 7000 series
    • Gen4 x8 with Ryzen 8000 (Phoenix 1)
    • Gen4 x4 with Ryzen 8000 (Phoenix 2)
  • 15µ gold contact in VGA PCIe slot (PCIE1)
  • If M2_3 is occupied, PCIE2 will be disabled

  • Storage

  • 1 x Blazing M.2 (M2_1, Key M), PCIe Gen5 x4 (128 Gb/s), type 2280
  • 2 x Hyper M.2 (M2_2, M2_3, Key M), PCIe Gen4 x4 (64 Gb/s), type 2280
  • 4 x SATA3 6.0 Gb/s connectors
  • Supports NVMe SSDs as boot disks
  • M2_1 is first priority for M.2 installation
  • M2_1:
    • Gen5 x4 with Ryzen 9000 & 7000 series
    • Gen4 x4 with Ryzen 8000 (Phoenix 1 & Phoenix 2)
  • M2_3:

    • Gen4 x4 with Ryzen 9000 & 7000 series
    • Gen4 x4 with Ryzen 8000 (Phoenix 1)
    • Gen4 x2 with Ryzen 8000 (Phoenix 2)
  • RAID Support

  • RAID 0, 1, 10 for SATA storage devices
  • RAID 0, 1, 10 for M.2 NVMe storage devices
  • Requires additional M.2 NVMe expansion cards for RAID 10

  • Audio

  • Realtek ALC897 7.1 CH HD Audio Codec
  • Nahimic Audio

  • Networking

  • Realtek Dragon RTL8125BG 2.5G LAN (10/100/1000/2500 Mb/s)
  • Dragon 2.5G LAN Software:

    • Smart auto adjust bandwidth control
    • Visual network usage statistics
    • Optimized default settings for game, browser, and streaming modes
    • User-customized priority control
  • USB Connectivity

  • Rear:
    • 1 x USB 3.2 Gen2 Type-C
    • 1 x USB 3.2 Gen2 Type-A (10 Gb/s)
    • 2 x USB 3.2 Gen1 Type-A
    • 4 x USB 2.0
  • Front (via headers):
    • 1 x USB 3.2 Gen1 Type-C
    • 4 x USB 3.2 Gen1 Type-A
    • 4 x USB 2.0
  • All USB ports support ESD protection

  • Cooling & Heatsinks

  • Supports M.2 bottom heatsink
  • M.2 bottom heatsink helps dissipate heat through the motherboard PCB to maintain performance and stability

  • DIY & Convenience Features

  • Pre-installed I/O shield to simplify installation
  • BIOS Flashback button
  • ASRock EZ Troubleshooter
  • ASRock Post Status Checker
  • ASRock Auto Driver Installer

  • Lighting & Fan Control

  • 1 x RGB LED header
  • 3 x addressable LED headers
  • Supports up to 12V/3A (36W) LED strip
  • Supports up to 5V/3A (15W) LED strip
  • 2 x CPU fan connectors (4-pin, Smart Fan Speed Control)
    • CPU_FAN1 supports up to 1A (12W)
    • CPU_FAN2 supports up to 3A (36W)
  • 3 x chassis fan connectors (4-pin, Smart Fan Speed Control), each up to 3A (36W)
  • CPU_FAN2 and CHA_FAN1–3 auto-detect 3-pin or 4-pin fans

  • Form Factor

  • Micro ATX
  • 9.6 in x 9.6 in / 30.5 cm x 24.4 cm

Specifications

Platform & Chipset

Category Details
Form Factor Micro ATX (9.6 in x 9.6 in / 30.5 cm x 24.4 cm)
Chipset AMD B850

CPU

Category Details
Socket AMD Socket AM5
Support Ryzen 9000, 8000 and 7000 Series Processors

Memory

Category Details
Technology Dual Channel DDR5 Memory
Slots 4 x DDR5 DIMM
Capacity Up to 256GB
Type DDR5 ECC/non-ECC, un-buffered
Supported Speeds Up to 8000+ (OC)
Profiles XMP and EXPO

Expansion Slots

Slot Details
PCIE1 1 x PCIe 5.0 x16, supports x16 mode
PCIE2 1 x PCIe 4.0 x4, supports x4 mode (disabled when M2_3 is occupied)
M.2 Key E 1 x M.2 (Key E, type 2230) for WiFi/BT PCIe wireless module
PCIe Behavior PCIE1: Gen5 x16 (9000/7000), Gen4 x8 (8000 Phoenix 1), Gen4 x4 (8000 Phoenix 2)
Contacts 15µ gold contact in VGA PCIe slot (PCIE1)

Graphics Output

Port Specifications
HDMI HDMI 2.1 TMDS/FRL 8G compatible, HDR, HDCP 2.3, up to 4K 120Hz
DisplayPort DisplayPort 1.4 with DSC, HDCP 2.3, up to 4K 120Hz
Integrated AMD RDNA graphics (actual support may vary by CPU)

Storage

Connector Details
M2_1 (Blazing) 1 x M.2 Key M, type 2280, PCIe Gen5 x4 (128 Gb/s)
M2_2 (Hyper) 1 x M.2 Key M, type 2280, PCIe Gen4 x4 (64 Gb/s)
M2_3 (Hyper) 1 x M.2 Key M, type 2280, PCIe Gen4 x4 (64 Gb/s) *
SATA 4 x SATA3 6.0 Gb/s
Boot Support NVMe SSDs supported as boot disks
Lane Behavior M2_1: Gen5 x4 (9000/7000), Gen4 x4 (8000 Phoenix 1/2)
M2_3: Gen4 x4 (9000/7000), Gen4 x4 (8000 Phoenix 1), Gen4 x2 (8000 Phoenix 2)
Notes M2_1 is first priority; if M2_3 is occupied, PCIE2 will be disabled

*Per vendor specification

RAID

Category Details
SATA RAID 0, RAID 1, RAID 10
M.2 NVMe RAID 0, RAID 1, RAID 10 (needs additional NVMe cards)

Audio

Category Details
Codec Realtek ALC897 7.1 CH HD Audio
Features Nahimic Audio

LAN

Category Details
Controller Realtek Dragon RTL8125BG 2.5 Gigabit LAN (10/100/1000/2500 Mb/s)
Software Dragon 2.5G LAN Software with bandwidth control and usage visualization

USB

Location Ports
Rear 1 x USB 3.2 Gen2 Type-C, 1 x USB 3.2 Gen2 Type-A, 2 x USB 3.2 Gen1 Type-A, 4 x USB 2.0
Front 1 x USB 3.2 Gen1 Type-C, 4 x USB 3.2 Gen1 Type-A, 4 x USB 2.0 (via headers)
Protection All USB ports support ESD protection

Rear Panel I/O

  • 2 x Antenna mounting points
  • 1 x HDMI port
  • 1 x DisplayPort 1.4
  • 1 x USB 3.2 Gen2 Type-A port (10 Gb/s)
  • 1 x USB 3.2 Gen2 Type-C port
  • 2 x USB 3.2 Gen1 ports
  • 4 x USB 2.0 ports
  • 1 x RJ-45 LAN port
  • 1 x BIOS Flashback button
  • HD audio jacks: Line in / Front speaker / Microphone

Internal Connectors & Headers

  • 1 x SPI TPM header
  • 1 x Power LED and speaker header
  • 1 x RGB LED header
  • 3 x Addressable LED headers
  • 2 x CPU fan connectors (4-pin, Smart Fan Speed Control)
  • 3 x Chassis fan connectors (4-pin, Smart Fan Speed Control)
  • 1 x 24-pin ATX power connector
  • 1 x 8-pin 12V power connector (Hi-Density)
  • 1 x 4-pin 12V power connector (Hi-Density)
  • 1 x Front panel audio connector
  • 2 x USB 2.0 headers (support 4 USB 2.0 ports)
  • 2 x USB 3.2 Gen1 headers (support 4 USB 3.2 Gen1 ports)
  • 1 x Front panel USB 3.2 Gen1 Type-C header

BIOS

  • 256Mb AMI UEFI Legal BIOS with GUI support

Software & UEFI

  • ASRock Motherboard Utility (A-Tuning)
  • ASRock Dragon 2.5G LAN Software
  • ASRock Polychrome SYNC
  • ASRock EZ Mode
  • ASRock Full HD UEFI
  • ASRock Auto Driver Installer
  • ASRock Instant Flash

Operating System Support

  • Microsoft Windows 10 64-bit
  • Microsoft Windows 11 64-bit

Certifications

  • FCC
  • CE
  • ErP/EuP ready (ErP/EuP ready power supply required)

Included Accessories

  • 2 x SATA data cables
  • 1 x Screw for M.2 socket

Unique & Convenience Features

  • Superb productivity with PCIe Gen5 (graphics, M.2) and Dual Channel DDR5
  • Rock-solid durability with 8+2+1 power phase and Dr.MOS
  • Pre-installed I/O shield for easier assembly
  • Ultrafast connectivity with 2.5G LAN and multiple USB 3.2 ports
  • EZ Update and troubleshooting:
  • BIOS Flashback button
  • ASRock Auto Driver Installer
  • EZ Troubleshooter
  • ASRock Post Status Checker

The ASRock B850M PRO RS is a feature-rich Micro ATX AM5 motherboard tailored for users seeking next-generation PCIe Gen5 storage and graphics support, fast DDR5 memory, 2.5G LAN, and comprehensive connectivity in a compact, builder-friendly design.