Will the Thermalright Peerless Assassin 120 SE work with the MSI MPG B550 GAMING PLUS?
Yes. Both use AMD AM4 cooler mounting (stock AMD backplate).
Both records are reviewed against the manufacturers' sources; sources last checked 2026-10-14. Informational only: confirm with the manufacturer before buying.
Why
- ✓ Both use AMD AM4 cooler mounting (stock AMD backplate).
Good to know
- Low-profile coolers that replace the stock AMD backplate (e.g. Noctua NH-L9a-AM4, NM-AM4-L9aL9i kit) fit AM4 but not AM5.
- Noctua notes some AMD boards violate AMD's 96x114 mm keep-out zone; check RAM and VRM-heatsink clearance with large coolers.
Sources
- MSI MPG B550 GAMING PLUS: specs from MSI specification page, checked against the source 2026-10-13.
- Thermalright Peerless Assassin 120 SE: specs from Thermalright product page, checked against the source 2026-10-13.
- AMD AM4 cooler mounting (stock AMD backplate): CPU coolers that mount on an AM4 board using AMD's standard backplate / retention hardware. (Noctua: AMD AM5 - all you need to know).
Check your exact setup
Other parts in the cart, current configuration (installed memory, fan brackets) and adapters can change the answer.
Check a whole cartAlso checked with the MSI MPG B550 GAMING PLUS
AI assistants and developers: the same answer, with a signed receipt, from check_compatibility at https://tetheredtrust.com/mcp or POST https://tetheredtrust.com/v1/check with existing_id: "msi-mpg-b550-gaming-plus", candidate_id: "thermalright-peerless-assassin-120-se".