MSI B550-A PRO ATX AM4 Motherboard
MSI
Motherboard

MSI B550-A PRO ATX AM4 Motherboard

Key Features

PCIe 4.0 RAID Support 1GbE Ethernet
MSRP: $139
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Technical Specifications

MSRP
$139
Manufacturer
MSI
Socket
AM4
Chipset
AMD B550
Form Factor
ATX
Memory
4 slots • max 128GB • DDR4 • speeds: DDR4-1866 to DDR4-4400 • No ECC
Expansion Slots
2x PCIe x16 • 2x PCIe x1 • 2x M.2 slots
Storage
6 SATA ports • SATA 6.0 Gb/s • RAID supported
Connectivity
Ethernet: 1 Gb/s • Wireless: None • Bluetooth None
USB Ports
1x USB 3 2 GEN 2 • 1x USB 3 2 GEN 1
Headers
2x USB 2 0 • 1x USB 3 2 GEN 1 • 1x USB 3 2 GEN 2
Video
Onboard: Depends on CPU
Back Connect
No
VRM Phases
10

Pros & Cons

Pros

  • Mature AM4 platform offers proven stability and wide CPU compatibility
  • Generous memory capacity support enables heavy multitasking and professional use
  • Balanced chipset offers good features with overclocking capabilities
  • Multiple PCIe x16 slots enable multi-GPU setups and professional expansion cards
  • Generous SATA port count supports large storage arrays and legacy drives
  • Full ATX form factor maximizes expansion slots and connectivity options
  • Good feature-to-price ratio provides solid capabilities at reasonable cost
  • MSI gaming focus with user-friendly features and RGB integration

Cons

  • Previous generation platform with limited future upgrade path
  • Basic connectivity features require additional hardware

Community Insights

  • A frequent topic among users is the motherboard’s strong price-to-performance ratio. Many builders praise the B550-A PRO for offering reliable power delivery, good VRM cooling, and stability with Ryzen 3000/5000 CPUs, making it a top pick for budget and mid-range systems.
  • Another popular discussion centers around BIOS compatibility, especially for newer Ryzen 5000 series CPUs. Some early users experienced the need for a BIOS update out of the box for full support, but most agree that MSI’s BIOS update process is straightforward and that the board now offers broad CPU and memory compatibility.

Frequently Asked Questions

Does the MSI B550-A PRO support Ryzen 5000 series CPUs out of the box?
Most newer boards ship with updated BIOS for Ryzen 5000 support, but if you receive older stock, you may need to update the BIOS first. MSI provides tools like BIOS Flashback for updating without a CPU installed.
How many M.2 slots and what PCIe generations are available?
The B550-A PRO includes two M.2 slots: one supports PCIe Gen4 (when using a Ryzen 3000/5000 CPU) for high-speed NVMe SSDs, and the other supports PCIe Gen3.

Performance Guide & Use Cases

Best For
Cost-effective gaming builds
Content creation workstations
Small business servers and NAS builds
Overkill Scenarios
Typical home computing and office work
Avoid For
Wireless-dependent setups without ethernet access
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