ASRock B850M Pro RS AM5 Micro-ATX Motherboard DDR5 PCIe 5.0
ASRock
ASRock B850M Pro RS AM5 Micro-ATX Motherboard DDR5 PCIe 5.0
The ASRock B850M Pro RS AM5 Micro-ATX Motherboard DDR5 PCIe 5.0 is a Micro-ATX platform built for AMD AM5 desktop builders who want a stable, efficient foundation for Ryzen 7000, 8000 and 9000 series processors without unnecessary complexity. It combines an 8+2+1 phase power design with a 6-layer PCB to support DDR5 memory overclocking up to 8000+ MT/s, and includes a PCIe 5.0 primary slot alongside three M.2 slots for flexible, fast storage.
Why this product
AMD AM5 Ready for Three Processor Generations
It supports Ryzen 7000, 8000 and 9000 series processors in the AM5 socket, giving builders flexibility across current and recent AMD platforms.
PCIe 5.0 Slot and Gen5 M.2 Storage
The primary x16 slot runs at PCIe 5.0, and the dedicated Blazing M.2 slot operates at PCIe Gen5 x4, supporting the fastest consumer SSDs currently available.
DDR5 OC up to 8000+ MT/s with XMP and EXPO
Four DDR5 DIMM slots support dual-channel operation up to 256 GB total, with pre-tested XMP and EXPO profiles for straightforward memory overclocking.
8+2+1 Phase Dr.MOS Power for CPU Stability
The Dr.MOS power stages cover VCore, SOC and MISC rails across an 8+2+1 phase arrangement, designed to maintain stable delivery under sustained CPU loads.
6-Layer PCB for Signal and Thermal Efficiency
The 6-layer PCB is intended to reduce signal interference and lower temperatures, which is particularly relevant when running memory at elevated frequencies.
BIOS Flashback for Hassle-Free Firmware Updates
BIOS Flashback lets you update firmware without a compatible CPU or memory installed, which is useful when preparing a board for a new processor generation.
- SocketAMD AM5
- ChipsetAMD B850
- Form FactorMicro-ATX
- Memory SupportDDR5, up to 256 GB, 8000+ MT/s (OC)
- Primary PCIe SlotPCIe 5.0 x16
- M.2 Slots3 (1× PCIe Gen5 x4, 2× PCIe Gen4 x4)
- LAN2.5 Gigabit (Realtek Dragon RTL8125BG)
- USB Rear1× USB 3.2 Gen2 Type-C, 1× USB 3.2 Gen2 Type-A, 2× USB 3.2 Gen1, 4× USB 2.0
- SKUASR-1845
- EAN4711581490345
- Compatible with AMD AM5 Ryzen 9000, 8000 and 7000 series desktop processors.
- Fits standard Micro-ATX cases and full-ATX cases that accept Micro-ATX boards.
- Accepts DDR5 ECC and non-ECC unbuffered DIMMs; does not support DDR4.
- Integrated display outputs (HDMI 2.1 and DisplayPort 1.4) work only with CPUs that include integrated AMD RDNA graphics — verify your chosen CPU before relying on these ports.
- Wi-Fi is not built in; the board includes an M.2 Key E slot (type 2230) for an optional PCIe Wi-Fi/Bluetooth module, sold separately.
- Not compatible with AMD AM4 processors or any Intel platform.
Best for
- AMD AM5 first-time builders who want a straightforward Micro-ATX layout with sensible defaults and pre-tested memory profiles rather than manual tuning.
- Compact desktop builds that need the smaller Micro-ATX footprint but still require PCIe 5.0 GPU bandwidth and fast Gen5 M.2 storage.
- Memory overclockers who want to run XMP or EXPO profiles up to 8000+ MT/s on a board designed with a 6-layer PCB for signal stability.
- Wired-network users who benefit from the included 2.5G LAN without needing to add a separate network card.
- Future upgraders who plan to move across Ryzen generations without changing their platform, given AM5 support across three processor series.
Trade-offs
- Wireless-first builds: Wi-Fi and Bluetooth are not included on-board and require purchasing a separate M.2 Key E module.
- Full-ATX builds with many expansion cards: only two PCIe slots are present — one x16 and one x4 — leaving no room for multiple discrete add-in cards.
- High-end enthusiast overclocking: the B850 chipset and 8+2+1 power design are positioned for stable daily use rather than extreme all-core voltage push on flagship Ryzen CPUs.
- Builders carrying over DDR4 memory: the board supports DDR5 only; existing DDR4 kits cannot be reused.
Modern and futuristic, with the attractive specifications and perfect balance, the Race Sport (RS) Edition is the evolution of the most popular PRO series motherboard.
Optimized for stability, durability, and efficiency. It combines reliable performance, user-friendly features and streamlined style for daily computing tasks.
The 6 Layer PCB provides stable signal traces and power shapes delivering lower temperature and higher energy efficiency for memory overclocking! Thus, it's able to support the latest memory modules with most extreme memory performance!
Derived from the "built for stable and reliable" designing concept, ASRock does not compromise on any details. This motherboard is built with high quality materials, enthusiasts are able to enjoy the boost of DDR5 memory overclocking performance by enabling the pre-tested profiles.
General
| Brand | ASRock |
|---|---|
| Model | B850M Pro RS |
| Form Factor | Micro-ATX |
| Chipset | AMD B850 |
| CPU Socket | AMD AM5 |
| CPU Support | Ryzen 9000, 8000 and 7000 series |
| PCB Layers | 6 |
| I/O Shield | Pre-installed |
Memory & Storage
| Memory Type | DDR5 (ECC and non-ECC, unbuffered) |
|---|---|
| DIMM Slots | 4 (Dual Channel) |
| Max Memory | 256 GB |
| Max Memory Speed (OC) | 8000+ MT/s |
| OC Profiles | XMP and EXPO |
| M.2 Slot 1 (Blazing) | PCIe Gen5 x4 |
| M.2 Slots 2–3 (Hyper) | PCIe Gen4 x4 (×2) |
| SATA Ports | 4 × SATA3 6.0 Gb/s |
| M.2 Bottom Heatsink | Supported |
Connectivity
| PCIe Slot 1 | PCIe 5.0 x16 (x16 mode) |
|---|---|
| PCIe Slot 2 | PCIe 4.0 x4 |
| Wi-Fi | Not built-in; M.2 Key E slot (type 2230) for optional module |
| LAN | 2.5G (10/100/1000/2500 Mb/s), Dragon RTL8125BG |
| USB Rear | 1× USB 3.2 Gen2 Type-C, 1× USB 3.2 Gen2 Type-A, 2× USB 3.2 Gen1, 4× USB 2.0 |
| USB Front Headers | 1× USB 3.2 Gen1 Type-C, 4× USB 3.2 Gen1, 4× USB 2.0 |
| Video Out | 1× HDMI 2.1 (up to 4K 120Hz), 1× DisplayPort 1.4 with DSC (up to 4K 120Hz) |
| Audio | 7.1 CH HD Audio, Realtek ALC897, Nahimic Audio |
Power & Features
| Power Design | 8+2+1 Phase, Dr.MOS (VCore+SOC+MISC) |
|---|---|
| BIOS Flashback | Yes |
| HDCP | 2.3 (HDMI and DisplayPort) |
| HDR | Supported (HDMI) |
Shipping
All our products are shipped from the United Kingdom within 24 to 48 hours of purchase. See our Shipping and Returns page for full details.
Returns
- Tech Syndicate offers a full money-back guarantee on all purchases made in our store. If you are not satisfied with your purchase, we will provide a full refund, no questions asked.
- Refunds are available within 45 days of delivery.
- After the 45-day period you are no longer eligible for a refund, so we encourage you to try the product within the first few weeks to make sure it fits your needs.