ASUS Prime B550M-A WiFi II AMD Micro ATX Motherboard with PCIe 4.0, WiFi 6, ECC Memory, HDMI 2.1, RGB Header
Bottom line: The ASUS Prime B550M-A WiFi II AMD Micro ATX Motherboard with PCIe 4.0: PCIe 4.0 x16 SafeSlot plus one PCIe 4.0 x4 M.2 for full-speed GPU and NVMe; main trade-off: micro ATX layout limits you to one PCIe x16 slot for expansion.
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Pros & Cons
Pros
- ✓ PCIe 4.0 x16 SafeSlot plus one PCIe 4.0 x4 M.2 for full-speed GPU and NVMe
- ✓ Onboard WiFi 6 (802.11ax) and 1Gb LAN, no add-in wireless card needed
- ✓ Dual M.2 slots let you run two NVMe SSDs on a micro ATX board
- ✓ ECC memory support, uncommon on a mainstream B550 micro ATX board
- ✓ HDMI 2.1 outputs 4K at 60Hz, plus legacy D-Sub and DVI for older displays
Cons
- ✗ Micro ATX layout limits you to one PCIe x16 slot for expansion
- ✗ 1Gb LAN only, so no 2.5Gb Ethernet at this price tier
- ✗ B550 chipset targets 3rd Gen Ryzen, not the newer AM5 socket
- ✗ D-Sub and DVI outputs eat back-panel space many builders will not use
Manufacturer description
The ASUS Prime B550M-A WiFi II is a micro ATX AM4 motherboard built for 3rd Gen AMD Ryzen builds that need current-generation bandwidth without a premium chipset price. Its PCIe 4.0 x16 SafeSlot feeds a modern GPU at full speed, while dual M.2 slots give you two NVMe SSDs, one of them wired for PCIe 4.0 x4 throughput. WiFi 6 (802.11ax) and 1Gb LAN cover wireless and wired networking on the same board, so a small-form-factor build skips the add-in card. Display output is unusually flexible for the segment: HDMI 2.1 drives 4K at 60Hz off a Ryzen APU, and D-Sub plus DVI keep older monitors and…
SpecPicks Verdict
SpecPicks scored ASUS Prime B550M-A WiFi II AMD Micro ATX Motherboard with PCIe 4.0 using a rating × review-volume × price-fit model applied to published specs and reviews across the motherboards category. Compare with similarly-priced alternatives in the motherboards category before committing. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for motherboards of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
Does the ASUS Prime B550M-A WiFi II have built-in WiFi?
Yes. WiFi 6 (802.11ax) is onboard alongside 1Gb LAN, so you can go wireless or wired without adding a PCIe network card.
How many M.2 SSD slots does this motherboard have?
Two M.2 slots for NVMe SSDs. One runs at PCIe 4.0 x4 for full next-gen SSD speed; check the ASUS listing for the second slot's exact lane spec.
Will this board fit in a micro ATX case?
Yes, it is a micro ATX board, so it fits micro ATX cases and most full ATX cases that support the smaller standoff pattern.
Does the ASUS Prime B550M-A WiFi II support ECC memory?
Yes, ECC memory support is listed among its features, which is unusual at this tier. ASUS OptiMem trace layout also targets higher memory clocks at lower voltage.
Key Features
- AMD AM4 Socket and PCIe 4.0: The perfect pairing for 3rd Gen AMD Ryzen CPUs
- Ultrafast Connectivity: 1x PCIe 4.0 x16 SafeSlot, WiFi 6 (802.11ax), 1Gb LAN, dual M.2 slots (NVMe SSD)—one with PCIe 4.0 x4 connectivity, USB 3.2 Gen 2 Type-A , HDMI 2.1 (4K at 60HZ), D-Sub & DVI
- Comprehensive Cooling: VRM heatsink, PCH heatsink, hybrid fan headers and Fan Xpert 2 utility
- 5X Protection III: all-round protection with LANGuard, DRAM overcurrent protection, overvoltage protection, SafeSlot Core safeguards and stainless-steel back I/O
- Boosted Memory Performance: ASUS OptiMem proprietary trace layout allows memory kits to operate at higher frequencies with lower voltages to maximize system performance.
Full Specifications
| Brand | ASUS |
|---|---|
| USB 2.0 | 11 |
| Platform | Windows 10 |
| CPU Model | Others |
| CPU Socket | Socket AM4 |
| Model Name | PRIME B550M-A WIFI II |
| Unit Count | 1 Count |
| Chipset Type | AMD B550 |
| Connectivity | USB, WiFi |
| Model Number | PRIME B550M-A WIFI II |
| Chipset Family | AMD B550 |
| Item Type Name | Computer motherbaord |
| Mfr Part Number | PRIME B550M-A WIFI II |
| Number of Items | 1 |
| Number of Ports | 13 |
| Total Usb Ports | 6 |
| Processor Socket | Socket AM4 |
| Total PCIe Ports | 3 |
| Total SATA Ports | 4 |
| 5X Protection III | all-round protection with LANGuard, DRAM overcurrent protection, overvoltage protection, SafeSlot Core safeguards and stainless-steel back I/O |
Ready to buy?
ASUS Prime B550M-A WiFi II AMD Micro ATX Motherboard with PCIe 4.0, WiFi 6, ECC Memory, HDMI 2.1, RGB Header is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
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