The primary x16 slot and first M.2 slot support PCIe Gen4 with compatible Ryzen processors.
1/6
OPCBLEU // PRODUCT
Product description
Description and product details Overview, features, specifications, compatibility and FAQ
AM4. B550. PCIe 4.0. DUAL M.2. USB 10Gbps. FLASH BIOS.
MSI B550-A PRO ProSeries AMD AM4 ATX Motherboard — Black
The MSI B550-A PRO is a professional-grade AMD B550 ATX motherboard designed for stable Ryzen performance, productivity, and gaming. MSI Core Boost, Digital PWM, a 2oz thickened copper PCB, and an extended heatsink design provide a dependable foundation for compatible Ryzen processors.
PCIe 4.0 graphics support, a PCIe 4.0 x4 M.2 slot, dual M.2 storage, six SATA ports, USB 3.2 Gen 2 Type-A and Type-C connectivity, Gigabit Ethernet, Audio Boost, and a dedicated Flash BIOS Button make it a practical and highly expandable AM4 platform.
PCIe 4.0graphics + NVMe
4400+DDR4 OC
10GbpsUSB Gen 2
Two M.2 slots provide flexible solid-state storage, including a CPU-connected PCIe 4.0 x4 slot.
Four DIMM slots support up to 128GB with A-XMP overclocked speeds depending on the configuration.
Update the BIOS using a USB drive without installing a CPU, memory, or graphics card.
Stable Performance
Core Boost + Digital PWM
MSI combines an optimized power layout with a digital PWM controller and enhanced PCB design for reliable CPU power delivery.
Core Boost
An optimized power circuit layout is designed to provide precise and consistent current to compatible Ryzen processors.
Digital PWM
A digital power controller helps maintain smooth operation under demanding workloads.
2oz Copper PCB
A thickened copper PCB improves electrical performance, heat dissipation, and long-term reliability.
Extended Heatsink
An enlarged PWM heatsink with high-conductivity thermal pads helps manage VRM temperatures.
Next-Gen Storage & Graphics
PCIe 4.0 + Lightning Gen4 M.2
PCIe 4.0 x16
The reinforced primary slot supports PCIe 4.0 x16 with compatible Ryzen processors.
Gen4 x4 M.2
The primary M.2 slot supports PCIe 4.0 x4 NVMe drives for high-bandwidth storage.
M.2 Shield Frozr
Integrated M.2 cooling helps reduce SSD thermal throttling during sustained transfers.
6× SATA 6Gb/s
Six SATA connectors provide extensive support for additional SSDs and hard drives.
High-Speed Connectivity
USB 3.2 Gen 2 10Gbps
Rear USB-C 10Gbps
A rear USB 3.2 Gen 2 Type-C port supports fast external storage and compatible peripherals.
Rear USB-A 10Gbps
A USB 3.2 Gen 2 Type-A port provides another high-speed 10Gbps connection.
Front USB-C Header
An internal USB 3.2 Gen 1 Type-C connector supports compatible modern cases.
Broad USB Support
Additional rear and internal USB 3.2 Gen 1 and USB 2.0 connectivity supports a wide peripheral ecosystem.
Professional Expansion
Flexible PCIe & Multi-GPU Support
PCIe Steel Armor
The primary expansion slot is reinforced to better support large graphics cards and reduce EMI interference.
Second x16 Slot
A secondary PCIe 3.0 x16 physical slot operates at up to x4 speed for compatible expansion devices.
2× PCIe x1
Two PCIe 3.0 x1 slots support sound cards, capture cards, adapters, and other expansion hardware.
AMD CrossFire
The platform supports 2-way AMD CrossFire configurations where compatible hardware is used.
Productivity & Gaming Essentials
Key Features
✓AMD AM4 socket with B550 chipset
✓Ryzen 5000 / 4000 G-Series / 3000 Series desktop processor support
✓4 × DDR4 DIMM slots, up to 128GB
✓DDR4 4400+ MHz A-XMP OC support depending on configuration
✓Core Boost and Digital PWM power design
✓2oz thickened copper PCB
✓Extended VRM heatsink with 7W/mK thermal pad
✓1 × PCIe 4.0 / 3.0 x16 primary slot
✓1 × PCIe 3.0 x16 physical slot operating up to x4
✓2 × PCIe 3.0 x1 slots
✓2 × M.2 slots including PCIe 4.0 x4 support
✓6 × SATA 6Gb/s connectors
✓Rear USB 3.2 Gen 2 Type-A + Type-C 10Gbps
✓Internal USB 3.2 Gen 1 Type-C connector
✓Realtek RTL8111H Gigabit LAN
✓Realtek ALC892 / ALC897 7.1-channel HD audio
✓HDMI 2.1 + DisplayPort display outputs for compatible APUs
✓Flash BIOS Button
✓Mystic Light RGB + JRAINBOW ARGB headers
✓ATX 30.5 × 24.4cm form factor
Versatile AM4 Platform
Perfect For
Stable PRO Platform
MSI PRO features prioritize reliability, connectivity, and expansion for professional workflows.
PCIe 4.0 Ready
Pair a compatible Ryzen CPU with a modern graphics card and PCIe 4.0 NVMe storage.
Dual M.2 + 6 SATA
Combine fast NVMe drives with multiple SATA devices for flexible capacity.
Flash BIOS Button
Firmware can be updated using a USB drive even without a CPU, RAM, or GPU installed.
Detailed Product Information
Technical Specifications
| Brand | MSI |
| Series | PRO Series |
| Model | B550-A PRO |
| Colour | Black / Graphite |
| Socket | AMD AM4 |
| Chipset | AMD B550 |
| CPU Support | AMD Ryzen 5000 / 3000 Series desktop processors and Ryzen 4000 G-Series desktop processors |
| Form Factor | ATX — 30.5 × 24.4cm |
| Memory | 4 × DDR4 DIMM, Dual Channel, up to 128GB |
| Memory OC | Up to DDR4-4400+ A-XMP OC; higher limits vary by DIMM configuration |
| Primary PCIe | 1 × PCIe 4.0 / 3.0 x16 |
| Secondary PCIe | 1 × PCIe 3.0 x16 physical slot, up to x4 |
| PCIe x1 | 2 × PCIe 3.0 x1 |
| M.2 Slots | 2 |
| M.2_1 | PCIe 4.0 / 3.0 x4 + SATA, up to 22110 |
| M.2_2 | PCIe 3.0 x4, up to 2280 |
| SATA | 6 × SATA 6Gb/s |
| Rear USB | 1 × USB 3.2 Gen 2 Type-C, 1 × USB 3.2 Gen 2 Type-A, 2 × USB 3.2 Gen 1 Type-A, 4 × USB 2.0 Type-A |
| Internal USB | 1 × USB 3.2 Gen 1 Type-C, 1 × USB 3.2 Gen 1 header for 2 ports, 2 × USB 2.0 headers for 4 ports |
| LAN | Realtek RTL8111H Gigabit Ethernet |
| Audio | Realtek ALC892 / ALC897 7.1-Channel HD Audio |
| Display Outputs | 1 × HDMI 2.1, 1 × DisplayPort |
| BIOS Flash | Flash BIOS Button |
| RGB Headers | 1 × 4-pin RGB + 2 × 3-pin JRAINBOW ARGB |
| CrossFire | 2-Way AMD CrossFire Support |
Shop With Confidence
Why Buy From OPCBleu?
A Reliable PRO-Series Foundation for Ryzen AM4.
The MSI B550-A PRO combines stable power design, PCIe 4.0, dual M.2 storage, extensive USB connectivity, and practical builder-friendly features.
🚚
Fast Canadian ShippingQuick order processing and delivery across Canada.
🛡️
30-Day ReturnsA clear return process for eligible purchases.
🔒
Secure CheckoutProtected payment processing through trusted providers.
💙
Quebec-Based StoreTechnology enthusiasts serving customers across Canada.
Helpful Answers
FAQs
Which processors are compatible with the MSI B550-A PRO?
MSI lists support for AMD Ryzen 5000 and 3000 Series desktop processors plus Ryzen 4000 G-Series desktop processors. Ryzen 5 3400G and Ryzen 3 3200G are specifically excluded.
Does the B550-A PRO support PCIe 4.0?
Yes. With a compatible processor, the primary x16 slot and first M.2 slot support PCIe 4.0.
How many M.2 SSDs can be installed?
Two M.2 drives can be installed. The first supports PCIe 4.0 / 3.0 x4 and SATA, while the second supports PCIe 3.0 x4.
Does the motherboard have a BIOS FlashBack feature?
Yes. MSI's Flash BIOS Button can update firmware from a USB drive without a CPU, memory, or graphics card installed.
How much DDR4 memory is supported?
The board has four DIMM slots and supports up to 128GB of DDR4 memory with A-XMP overclocking support.
Does it have 2.5Gb Ethernet?
No. The B550-A PRO uses a Realtek RTL8111H Gigabit Ethernet controller.
1/6
