ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen™) microATX Commercial Motherboard
Bottom line: The ASUS Prime B550M-A/CSM AMD AM4 microATX Commercial Motherboard ($137.58 on Amazon as of 2026-10-06): PCIe 4.0 support paired with 3rd Gen AMD Ryzen AM4 CPUs; main trade-off: microATX layout limits expansion vs full ATX B550.
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*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
Pros & Cons
Pros
- ✓ PCIe 4.0 support paired with 3rd Gen AMD Ryzen AM4 CPUs
- ✓ ECC memory support for added data integrity
- ✓ HDMI 2.1, D-Sub and DVI outputs drive 4K@60Hz
- ✓ USB 3.2 Gen 2 Type-C and Type-A connectivity
Cons
- ✗ microATX layout limits expansion vs full ATX B550
- ✗ 1Gb LAN only, no 2.5Gb Ethernet
- ✗ No onboard Wi-Fi
- ✗ Commercial CSM focus, minimal gaming RGB features
Manufacturer description
Powered by AMD 3rd Gen Ryzen processors, the ASUS Prime B550M-A/CSM commercial motherboard provides enhanced enterprise level features, including comprehensive system protection, 24/7 stability & reliability, an improved management suite with ASUS Control Center Express, ASUS Corporate Stable Model complimentary advance replacement, and a long product life cycle for reliable sourcing and support. Free 3-months Adobe Creative Cloud Subscription: Receive complimentary access with the purchase of this product (offer valid from 9/15/2021 to 9/15/2022) visit…
SpecPicks Verdict
SpecPicks scored ASUS Prime B550M-A/CSM AMD AM4 microATX Commercial Motherboard 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.
Key Features
- AMD AM4 Socket and PCIe 4. 0: The perfect pairing for 3rd Gen AMD Ryzen CPUs. Operating System-Windows 10 64-bit
- Fast Connectivity: 1Gb LAN, USB 3. 2 Gen 2 Type-C & Type-A ports, a front panel USB 3. 2 Gen 1 connector, plus HDMI 2. 1, D-Sub, and DVI display outputs
- First PCIe 4. 0 CSM motherboard: ASUS Corporate Stable Model with up to 36-month supply, EOL notice, and ECN control
- ASUS Control Center Express(ACCE) to make IT endpoint management simpler
- 5X Protection III: all-round protection with LANGuard, DRAM overcurrent protection, overvoltage protection, SafeSlot Core safeguards and stainless-steel back I/O
Full Specifications
| Brand | ASUS |
|---|---|
| USB 2.0 | 4 |
| Platform | Windows 10 |
| CPU Model | Others |
| CPU Socket | Socket AM4 |
| Model Name | PRIME B550M-A/CSM |
| Chipset Type | AMD AM4 |
| Connectivity | USB |
| Model Number | PRIME B550M-A/CSM |
| Item Type Name | ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen™) microATX commercial motherboard (PCIe 4.0, ECC memory, 1Gb LAN, HDMI 2.1/D-Sub, 4K@60HZ, TPM, ASUS Control Center Express) |
| Mfr Part Number | PRIME B550M-A/CSM |
| Number of Ports | 14 |
| Total Usb Ports | 4 |
| Processor Socket | Socket AM4 |
| Total PCIe Ports | 2 |
| 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 |
| Fast Connectivity | 1Gb LAN, USB 3. 2 Gen 2 Type-C & Type-A ports, a front panel USB 3. 2 Gen 1 connector, plus HDMI 2. 1, D-Sub, and DVI display outputs |
| Compatible Devices | Personal Computer |
| Memory Clock Speed | 4400 MHz |
| Full listing title | ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen™) microATX Commercial Motherboard (PCIe 4.0, ECC Memory, 1Gb LAN, HDMI 2.1/D-Sub, 4K@60HZ, TPM, ASUS Control Center Express) |
Ready to buy?
ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen™) microATX Commercial Motherboard (PCIe 4.0, ECC Memory, 1Gb LAN, HDMI 2.1/D-Sub, 4K@60HZ, TPM, ASUS Control Center Express) 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.
*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
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