Model

Brand	MSI
Series	PRO
Model	B550-A PRO

Supported CPU

CPU Socket Type	AM4
CPU Type	Supports AMD Ryzen 5000 Series / 4000 G-Series / 3000 Series processors * * Not compatible with AMD Ryzen 5 3400G & Ryzen 3 3200G.

Chipsets

Chipset	AMD B550

Memory

Number of Memory Slots	4×288pin
Memory Standard	DDR4 4400+ / 4266 / 4133 / 4000 / 3866 / 3733 / 3600 / 3466 / 3200 / 3066 / 3000 / 2933 / 2800 / 2667 by A-XMP OC MODE DDR4 3200 / 3066 / 3000 / 2933 / 2800 / 2667 / 2400 / 2133 / 1866 by JEDEC 1DPC 1R Max speed 4800 1DPC 2R max speed 3866 2DPC 1R max speed 4000 2DPC 2R max speed 3600
Maximum Memory Supported	128GB
Channel Supported	Dual Channel
ECC Supported	Non-ECC
Buffer Supported	Un-buffered

Expansion Slots

PCI Express 4.0 x16	1 x PCI Express 4.0 x16* * Actual support may vary by CPU.
PCI Express 3.0 x16	1 x PCI Express 3.0 x16* * Supports x4 speed. * When installing PCIe SSD in M.2_2, PCI_E3 slot will be unavailable.
PCI Express x1	2 x PCIe 3.0 x1

Storage Devices

SATA 6Gb/s	6 x SATA 6Gb/s
M.2	2 x M.2 slots (Key M): M2_1 slot (from AMD Processor): Supports PCIe 4.0/3.0 x4 * Supports SATA 6Gb/s Supports 2242/2260/2280/22110 storage devices M2_2 slot (from AMD B550 chipset): Supports PCIe 3.0 x4 Supports 2242/2260/2280 storage devices * The supported specification depends on installed processor.
SATA RAID	0/1/10

Onboard Video

Onboard Video Chipset	Supported only by CPU with integrated graphic

Onboard Audio

Audio Chipset	Realtek ALC892/ALC897
Audio Channels	7.1 Channels

Onboard LAN

LAN Chipset	Realtek RTL8111H
Max LAN Speed	10/100/1000Mbps

Rear Panel Ports

Back I/O Ports	1 x DisplayPort 1 x HDMI 1 x LAN (RJ45) 1 x PS/2 Keyboard/Mouse Combo 1 x USB 3.2 Gen 2 Type-A 1 x USB 3.2 Gen 2 Type-C 2 x USB 3.2 Gen 1 Type-A 4 x USB 2.0/1.1 6 x Audio Jacks Flash BIOS Button

Internal I/O Connectors

Onboard USB	1 x USB 3.2 Gen 1 5Gbps Type-C port 1 x USB 3.2 Gen 1 5Gbps connector (supports additional 2 USB 3.2 Gen 1 5Gbps ports) 2 x USB 2.0 connectors (supports additional 4 USB 2.0 ports)
Other Connectors	1 x 4-pin CPU fan connector 1 x 4-pin water-pump fan connector 6 x 4-pin system fan connectors 1 x Front panel audio connector 2 x System panel connectors 1 x Chassis Intrusion connector 1 x 4-pin RGB LED connector 2 x 3-pin RAINBOW LED connectors 1 x TPM module connector 1 x Clear CMOS jumper

Physical Spec

Form Factor	ATX
LED Lighting	RGB
Dimensions (W x L)	12.0" x 9.6"
Power Pin	1 x 24-pin ATX main power connector 1 x 8-pin ATX 12V power connector

Windows 11 Compatibility

Windows 11	Supported

Features

Features

Supports AMD Ryzen 5000 & 3000 Series desktop processors (not compatible with AMD Ryzen 5 3400G & Ryzen 3 3200G) and AMD Ryzen 4000 G-Series desktop processors Supports DDR4 Memory, up to 4400(OC) MHz Lightning Fast Experience: PCIe 4.0, Lightning Gen4 x4 M.2 with M.2 Shield Frozr, AMD Turbo USB 3.2 Gen 2 Premium Thermal Solution: Extended Heatsink Design with additional choke thermal pad and 7W/mK pad, and M.2 Shield Frozr are built for high performance system and non-stop works Powerful Design: Core Boost, Digital PWM IC, 2oz Thickened Copper PCB, Creator Genie, DDR4 Boost Audio Boost: Reward your ears with studio grade sound quality Multi-GPU: With Steel armor PCI-E slots. Supports 2-Way AMD Crossfire Dragon Center: A brand new software which integrates all MSI exclusive tools with user friendly user interface