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.
