This article covers ASUS PRIME B550M-A WIFI II AMD Ryzen 5000シリーズ AM4 対応 B550 搭載 mATX マザーボード.

Overview

The ASUS PRIME B550M-A WIFI II is a micro-ATX motherboard built around the AMD B550 chipset, designed for Socket AM4 processors including the Ryzen 5000 series. It integrates Wi-Fi 6 and Bluetooth 5.2 directly on the board, eliminating the need for a separate wireless card. With support for up to 128GB of DDR4 memory and a PCIe 4.0 x16 slot, this board offers a solid foundation for a mid-range gaming or productivity PC.
Positioned as a cost-effective solution for builders who want modern features without breaking the bank, the PRIME B550M-A WIFI II strikes a balance between price and capability. It's especially appealing for first-time builders or those upgrading from older AM4 platforms who want to keep their DDR4 memory and reuse existing components.

Compatibility Guide

This motherboard uses the AM4 socket and officially supports AMD Ryzen 5000, 5000G, 4000G, and 3000 series desktop processors. Memory support includes DDR4-3200 (OC) across four DIMM slots, with a maximum capacity of 128GB. The mATX form factor (24.4cm x 24.4cm) fits most compact cases while still offering decent expansion.
Expansion slots include one PCIe 4.0 x16 (for graphics cards) and two PCIe 3.0 x1 slots. Storage options are two M.2 slots (one PCIe 4.0 x4, one PCIe 3.0 x4) and four SATA 6Gb/s ports. Power delivery uses a standard 24-pin ATX main connector plus an 8-pin EPS12V CPU power connector, compatible with most ATX power supplies.

Product Info

Released in early 2022, the ASUS PRIME B550M-A WIFI II sits in the entry-to-mid-range segment of the motherboard market. Its key differentiator is the inclusion of Wi-Fi 6 at a price point where many competitors still require an add-on card. The board comes with a standard three-year warranty through ASUS's official channels.
Key specifications: AMD B550 chipset, 4x DDR4 DIMM slots (max 128GB), 2x M.2 slots, 1x PCIe 4.0 x16, Realtek 1Gb Ethernet, Wi-Fi 6 + Bluetooth 5.2, mATX form factor.

Best Use Cases

  • Budget Gaming Builds: Pair with a Ryzen 5 5600X or Ryzen 7 5700X and a mid-range GPU like the RTX 3060 or RX 6600 for smooth 1080p/1440p gaming. The PCIe 4.0 slot ensures no bottleneck with modern graphics cards.
  • Home Office / Media Center: Use with a Ryzen 5 4600G or 5700G APU for a compact, quiet PC that handles office tasks, 4K video playback, and light photo editing. Built-in Wi-Fi keeps the desk clutter-free.
  • First-Time PC Builders: The mATX size is easier to work with in smaller cases, and ASUS's UEFI BIOS offers an intuitive EZ Mode for beginners. The price is forgiving if mistakes happen.
    Not recommended for users who need PCIe 5.0, DDR5 memory, or multiple full-length PCIe slots for multi-GPU setups.

Things to Consider

One limitation is that only the primary M.2 slot (M.2_1) supports PCIe 4.0; the second slot runs at PCIe 3.0. Additionally, the board lacks BIOS Flashback, so updating the BIOS requires a compatible CPU installed. For Ryzen 5000 series users this is not an issue, but those buying a used 3000-series CPU to update the BIOS should plan accordingly.
The VRM design is adequate for 6- and 8-core Ryzen processors but may struggle with sustained all-core loads on a Ryzen 9 5950X. If you plan to run a 12- or 16-core CPU under heavy workloads, consider a board with better VRM cooling.
Competitors include the ASRock B550M Pro4 and Gigabyte B550M AORUS ELITE. The PRIME B550M-A WIFI II stands out for its integrated Wi-Fi 6, but its VRM and audio codec are more basic than some rivals.

FAQ

Q: Can I use a Ryzen 7 5800X3D on this board?
A: Yes, with BIOS version 2423 or later. However, due to the modest VRM, ensure adequate case airflow if running CPU-intensive tasks for extended periods.
Q: Does the second M.2 slot support PCIe 4.0?
A: No. Only the M.2_1 slot (connected to the CPU) supports PCIe 4.0 x4. The M.2_2 slot is limited to PCIe 3.0 x4 via the chipset.
Q: Is DDR4-3600 memory supported?
A: Officially, the board supports up to DDR4-3200 (OC). Many users have successfully run DDR4-3600 kits, but stability depends on the CPU's memory controller and the specific memory modules.

Product Disclosure (Amazon)

  • Manufacturer: ASUS
  • Seller: Amazon.co.jp
  • Fulfilled by: Amazon.co.jp
  • ASIN: B09NTMTJTR
  • Note: This article covers a manufacturer-made product based on Amazon listing details.