MSI MAG B550M Mortar MAX DDR4 AMD Motherboard

The MSI MAG B550M Mortar MAX is a Micro-ATX motherboard built on AMD’s B550 chipset for the AM4 socket, offering a compact yet feature-rich foundation for AMD Ryzen 5000 Series, 5000 G-Series, 4000G-Series, and 3000 Series processors. At 9.6 in. x 9.6 in. (24.4 cm x 24.4 cm), it fits standard Micro-ATX cases while delivering connectivity and thermal capabilities more commonly associated with full-size boards. Memory support extends to four DDR4 DIMM slots with a combined maximum of 128 GB. JEDEC-rated speeds range from 1866 MHz up to 3200 MHz, while A-XMP overclocking profiles allow modules to run at up to 4400+ MHz (1DPC 1R configuration). The dual-channel architecture supports non-ECC unbuffered DIMMs and ECC UDIMMs operated in non-ECC mode. For storage, the board provides six SATA 6 Gb/s ports and two M.2 Key-M slots. The primary M.2 slot draws lanes directly from the AMD processor and supports PCIe 4.0/3.0 x4 as well as SATA, while the secondary M.2 slot connects through the B550 chipset at PCIe 3.0 x4. MSI’s M.2 Shield Frozr thermal solution is fitted over the primary slot to manage SSD temperatures under sustained workloads. RAID 0, 1, and 10 are available for SATA drives; RAID 0 and 1 are available for M.2 NVMe devices. Connectivity is a standout strength. A Realtek RTL8125B controller delivers 2.5 Gbps wired LAN, while the pre-installed AMD Wi-Fi 6E module supports 802.11a/b/g/n/ac/ax across 2.4 GHz, 5 GHz, and 6 GHz bands with MU-MIMO TX/RX and Bluetooth 5.2. The back panel includes two USB 3.2 Gen 2 10 Gbps ports (one Type-A, one Type-C), two USB 3.2 Gen 1 5 Gbps Type-A ports, USB 2.0 ports, HDMI 2.1, DisplayPort 1.4, a PS/2 combo port, optical S/PDIF output, and a Flash BIOS button for convenient firmware updates without a CPU installed. Audio is handled by a Realtek ALC1220P codec delivering 7.1-channel high-definition audio with S/PDIF output. The power delivery stage uses an 8+2+1 Duet Rail Power System with Digital PWM and Core Boost, backed by an extended heatsink design featuring a choke thermal pad rated at 7 W/mK and a PCB with 2 oz thickened copper layers. RGB lighting headers include one 4-pin RGB and two 3-pin RAINBOW (ARGB) connectors for customisation via MSI’s Mystic Light ecosystem. Key Verified Specifications: – Socket: AM4 | Chipset: AMD B550 – CPU Compatibility: AMD Ryzen 5000, 5000G, 4000G, 3000 Series – Form Factor: Micro-ATX, 9.6 in. x 9.6 in. (24.4 cm x 24.4 cm) – Memory: 4x DDR4, up to 128 GB, up to 4400+ MHz (A-XMP OC) – Primary M.2: PCIe 4.0/3.0 x4 + SATA (processor lanes) – Secondary M.2: PCIe 3.0 x4 (B550 chipset lanes) – SATA: 6x SATA 6 Gb/s | RAID 0/1/10 (SATA), RAID 0/1 (NVMe) – Expansion: 1x PCIe 4.0/3.0 x16, 1x PCIe 3.0 x16 (x4 mode), 2x PCIe 3.0 x1 – Multi-GPU: 2-Way AMD CrossFire – LAN: Realtek RTL8125B 2.5 Gbps – Wireless: AMD Wi-Fi 6E (802.11ax, 2.4/5/6 GHz), Bluetooth 5.2 – Display Output: HDMI 2.1 (4096×2160 @60Hz), DisplayPort 1.4 (4096×2160 @60Hz) – Audio: Realtek ALC1220P, 7.1-channel HD Audio, S/PDIF output – USB (rear): 2x USB 3.2 Gen 2 10Gbps (Type-A + Type-C), 2x USB 3.2 Gen 1 5Gbps Type-A, 2x USB 2.0 Type-A – OS Support: Windows 11 64-bit, Windows 10 64-bit – Warranty: 3 Years