ASUS PRIME B850-PLUS-CSM AMD B850 ATX Motherboard DDR5
ASUS
ASUS PRIME B850-PLUS-CSM AMD B850 ATX Motherboard DDR5
The ASUS PRIME B850-PLUS-CSM is a mid-range AMD B850 ATX motherboard built for Ryzen 9000, 8000, and 7000 series processors. It delivers solid performance for gaming, content creation, and everyday computing with an 8+2+1 power phase design, DDR5 support, and AI PC readiness.
Why this product
PCIe 5.0 storage and expansion
One M.2 slot runs at PCIe 5.0 speeds for next-generation NVMe drives, with two additional PCIe 4.0 slots for flexibility. The primary expansion slot supports PCIe 5.0 graphics cards on Ryzen 9000 and 7000 systems.
Stable power delivery for overclocking
An 8+2+1 phase digital power design with discrete MOSFETs and dual VRM heatsinks ensures clean power to the CPU and memory, supporting DDR5 speeds up to 8000+ MT/s via EXPO and AEMP tuning.
Rear USB 10Gbps connectivity
Four USB 10Gbps ports (three Type-A and one Type-C) on the rear I/O plus additional USB 5Gbps options provide fast peripheral transfers and charging.
Advanced cooling architecture
Multiple heatsinks, thermal pads, and hybrid fan headers including dedicated CPU, CPU Optional, and AIO Pump connectors keep the system cool under load.
- ChipsetAMD B850
- SocketAM5
- Form FactorATX
- Memory Slots4 x DIMM
- M.2 Slots3 (PCIe 5.0 x4, PCIe 4.0 x4, PCIe 4.0 x2)
- Rear USB 10Gbps4 ports (3 Type-A, 1 Type-C)
- Power Design8+2+1 phase digital
- SKUASU-2701
- EAN4711387982037
- Supports AMD Ryzen 9000, 8000, and 7000 series processors in Socket AM5, up to 170W TDP.
- Accepts up to four DDR5 DIMM modules for a maximum of 256GB, with support for ECC and non-ECC memory.
- Runs Windows 11 or Windows 10 64-bit operating systems.
- PCIe 5.0 GPU slot operates at x16 on Ryzen 9000 and 7000 systems; Ryzen 8000 systems use PCIe 4.0 x8 mode on the primary slot.
- M.2_1 slot runs PCIe 5.0 on Ryzen 9000 and 7000 systems but PCIe 4.0 on Ryzen 8000 systems.
Best for
- Ryzen 9000 and 7000 series builders seeking PCIe 5.0 GPU and storage performance
- DDR5 overclockers who want tuning headroom via EXPO and AEMP profiles
- Builders who need extensive USB connectivity and fast front-panel expansion
- AI PC-ready systems requiring stable, feature-rich mid-range platform
Trade-offs
- Ryzen 8000 processors limited to PCIe 4.0 on the primary GPU and M.2_1 slots
- Builders needing more than four SATA 6Gb/s ports; this board offers exactly four
- Systems requiring RAID 5 or RAID 10 support with Ryzen 8000 processors; limited to RAID 0/1
- Compact or ITX form-factor builds; this is a full-size 12 × 9.6 inch ATX board
ASUS Prime series motherboards are expertly engineered to unleash the full potential of AMD Ryzen™ 9000 series processors. The PRIME B850-PLUS-CSM motherboard provides users and PC DIY builders with a range of performance optimizations via intuitive software and firmware features. It's designed to be Advanced AI PC-ready, offering the power and connectivity needed for demanding AI applications.
Digital Power Design
PRIME B850-PLUS-CSM features an 8+2+1 phase power design with discrete MOSFETs, ensuring efficient and stable power delivery for AMD processors plus steady performance for day-to-day use.
Three M.2 slots (up to 128 Gbps)
PRIME B850-PLUS-CSM offers a total of three M.2 slots, including one that supports data-transfer speeds of up to 128 Gbps via PCIe 5.0, and two that support PCIe 4.0.
Enhanced DDR5 performance
Comprehensive memory tuning options are the cornerstone of PRIME motherboards. The PRIME B850-PLUS-CSM maximizes the potential of your DDR5 modules, from entry-level to extreme-speed kits.
Cooler by design
The PRIME B850-PLUS-CSM motherboard is engineered with multiple onboard heatsinks and an array of hybrid fan headers to help ensure your rig stays cool and stable under intense workloads.
VRM heatsinks and thermal pads
Two massive VRM heatsinks and essential thermal pads improve heat transfer from the MOSFETs and chokes for better cooling performance.
Empowering connections
This motherboard offers a versatile range of connectivity, including support for PCIe 5.0 slot and an arsenal of USB ports which includes Type-C® connections.
USB 10Gbps Type-C®
A batch of USB ports support high-end rigs loaded with peripherals, including a rear USB Type-C® connector with ultrafast USB 10Gbps for transmission speeds of up to 10Gbps.
General
| Brand | ASUS |
|---|---|
| Model | PRIME B850-PLUS-CSM |
| Form Factor | ATX (12 in × 9.6 in) |
CPU & Memory
| Socket | AM5 (Ryzen 9000, 8000, 7000 series, up to 170W) |
|---|---|
| Memory Slots | 4 x DIMM |
| Max Memory | 256GB DDR5 |
| Memory Speeds | Up to 8000+ MT/s (OC) with Ryzen 9000, 8000, 7000 series |
| Memory Features | EXPO, AEMP, ECC/Non-ECC support |
| Power Phases | 8+2+1 with discrete MOSFETs |
Storage & Expansion
| M.2 Slot 1 | Type 2280, PCIe 5.0 x4 (Ryzen 9000/7000); PCIe 4.0 x4 (Ryzen 8000) |
|---|---|
| M.2 Slot 2 | Type 2280, PCIe 4.0 x4 (Ryzen 9000/7000); PCIe 4.0 x4/x2 (Ryzen 8000) |
| M.2 Slot 3 | Type 2242/2260/2280/22110, PCIe 4.0 x2 |
| SATA Ports | 4 x SATA 6Gb/s |
| GPU Expansion | 1 x PCIe 5.0 x16 (Ryzen 9000/7000); PCIe 4.0 x16 in x8/x4 (Ryzen 8000); 1 x PCIe 4.0 x16 in x4 mode |
| RAID Support | Ryzen 9000: RAID 0/1/5/10; Ryzen 8000: RAID 0/1; Ryzen 7000: RAID 0/1/10 |
Connectivity & Audio
| Rear USB 10Gbps | 4 ports (3 x Type-A, 1 x Type-C) |
|---|---|
| Rear USB 5Gbps | 2 x Type-A |
| Rear USB 2.0 | 2 x Type-A |
| Front USB Headers | 1 x USB 5Gbps Type-C connector, 1 x USB 5Gbps header (2 ports), 2 x USB 2.0 headers (4 ports) |
| Ethernet | 1 x Realtek 2.5Gb with LANGuard |
| Video Outputs | 1 x DisplayPort 1.4 (8K@30Hz), 1 x HDMI 2.1 (4K@60Hz) |
| Audio | Realtek 7.1 surround, 24-bit/192 kHz, dedicated audio layers |
Cooling & Power
| Fan Headers | 1 x CPU, 1 x CPU OPT, 1 x AIO Pump, 4 x Chassis (all 4-pin) |
|---|---|
| VRM Heatsinks | 2 x massive heatsinks with thermal pads |
| Power Connectors | 1 x 24-pin Main, 1 x 8-pin CPU, 1 x 4-pin CPU +12V |
Internal Headers & Features
| RGB Headers | 3 x Addressable RGB Gen 2 |
|---|---|
| Other Internal | Clear CMOS, Chassis Intrusion, COM Port, Front Panel Audio, S/PDIF Out, SPI TPM (14-1 pin), System Panel (10-1 pin), Thunderbolt/USB4 |
| BIOS | 256 Mb Flash ROM, UEFI AMI, BIOS FlashBack |
| Back Panel Features | BIOS FlashBack button, I/O Shield pre-mounted, SafeSlot, Aura Sync RGB control, FAN Xpert 2+ |
Software & OS
| OS Support | Windows 11, Windows 10 64-bit |
|---|---|
| Management | WOL by PME, PXE |
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.