ASUS Prime B550-PLUS AM4 ATX Motherboard: features, specs and who it suits

The ASUS Prime B550-PLUS is an ATX motherboard for AMD's AM4 socket. It is the foundation of a desktop PC: the processor, memory, storage and graphics card all plug into it. ASUS positions it for mainstream users and DIY builders who want PCIe 4.0 and a sensible set of features on an AM4 platform.

Which processors it fits

The AM4 socket and B550 chipset are made for AMD Ryzen 5000 (Zen 3) and 3rd Gen Ryzen processors, which is what ASUS lists. Before buying a particular processor, check the CPU support list for this board on the maker's website, since a given model can need a minimum firmware (BIOS) version.

What PCIe 4.0 means here

PCIe is the connection between the processor and add-in parts. PCIe 4.0 offers double the bandwidth per lane of PCIe 3.0. The board has one PCIe 4.0 x16 SafeSlot for a graphics card, and one of its two M.2 slots runs at PCIe 4.0 x4 for an NVMe SSD. Fast storage is one place where the extra bandwidth is easy to notice, though only if the SSD and the processor both support PCIe 4.0.

Storage, networking and display

Two M.2 slots take NVMe SSDs, which are small and plug directly into the board without cables. Wired networking is a 1Gb LAN port, and ASUS lists LANGuard protection on it. USB 3.2 Gen 2 Type-A is included, along with a Thunderbolt 3 header for an add-in card.

For display, the board has HDMI 2.1 and DisplayPort 1.2, with 4K at 60Hz listed. Video outputs on a motherboard work only with processors that include integrated graphics. With a Ryzen model that has none, you will connect your monitor to a graphics card instead.

Cooling and protection

The board has heatsinks on the VRM (the circuitry that feeds power to the processor) and on the chipset. It provides hybrid fan headers, which take either 3-pin or 4-pin fans, and the Fan Xpert 2 utility for adjusting fan behaviour.

ASUS describes its 5X Protection III as covering LANGuard, DRAM overcurrent protection, overvoltage protection, SafeSlot Core reinforcement and a stainless-steel rear I/O panel.

Memory and lighting

ASUS says its OptiMem trace layout lets memory kits run at higher frequencies with lower voltages. The listing also mentions ECC memory support; ECC works only with compatible processors and modules, so check the manual if you need it. An addressable Gen 2 RGB header and Aura Sync support let you connect compatible lighting strips and sync them.

What to check before you buy

• Case size: this is a full ATX board, about 12 x 9.6 inches in the standard form, so confirm that your case supports ATX.
• Processor support and any BIOS update the specific processor needs.
• Memory type: AM4 boards use DDR4, not DDR5.
• How many M.2 drives, SATA drives and fans you plan to connect.
• Whether you need built-in Wi-Fi, which the listing does not mention.

The short version

• ASUS Prime B550-PLUS: an ATX motherboard for AMD AM4 processors, including Ryzen 5000 and 3rd Gen Ryzen.
• PCIe 4.0 x16 slot and two M.2 slots, one at PCIe 4.0 x4.
• 1Gb LAN, HDMI 2.1, DisplayPort 1.2 and a Thunderbolt 3 header.
• VRM and chipset heatsinks, hybrid fan headers, and an addressable RGB header.

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