I got Asus ROG Strix LC II 360 ARGB from my local large PC component vendor. And installed it to my new Ryzen 7950 x3d setup (AM5). In the install instructions inside the packaging the AM4 was referenced, but there was no mention of AM5 at all. I didn't think anything of it, as the product page at the component vendor's web site included AM5 compatibility. I just assumed the same bracket is used for AM5 and AM4 (only one AMD bracket in the retail package). But there was a mistake in the component vendor's product page that stated AM5 compatibility right there in the product information. After installing and reading more information from the forums and other pages, I discovered that the LC II 360 ARGB would require a separate AM5-specific install bracket for the CPU.
I am however running the setup now with decent temperatures, albeit I have no clue what it could/should be. Temperatures are around 55-65C in normal Gaming (Microsoft Flight Simulator, X-Plane 12).
Question: Is the install with AM4 bracket sufficient (for AM5 Ryzen and Asus X670E TUF Gaming plus) for cooling or am I missing considerable cooling power due to not using the correct bracket? Also, do I risk damaging the CPU with the AM4 bracket? It's installed securely. I have an option now to return the product (vendor says AM5 bracket availability is "poor"), which obviously means tearing down the setup and replacing this with something else. Not something that I want to do, but if I must I will. Is the right bracket critical?
May I ask whether the bracket you mentioned is part code E in the parts list of the user manual?
If yes, this part is the Compatible Mounting Bracket for AM4 and AM5.
If this is not the part you are asking for, please provide a photo so we can better understand your problem.
Pre-AM5 Asetek 7th gen coolers like the Strix LC II originally shipped with a different AMD mounting kit (Asetek part number 35‐150‐1000015 for the standalone kit). It just used standoffs and thumbscrew nuts, no collars.
Around the time of AM5 launching, the existing coolers all changed to ship with a slightly different AMD mounting kit (Asetek part number 35‐150‐1000056 for the standalone kit). It uses standoffs, reversible collars, and thumbscrew nuts. The collars are fitted over the standoffs in a different orientation for AM4 vs AM5, for a very small difference in Z height or mounting pressure.
It's unclear to me exactly why Asetek decided to update the AMD kit for AM5, given that AMD supposedly designed AM5 to have the same Z height as AM4, but Asetek did make a change. It may well be related to mounting pressure, as the AM5 LGA socket is less tolerant of excess pressure than the AM4 PGA socket. ROG coolers manufactured before that change will have the old kit without the standoff collars, and newer ones have the new kit with the collars. It was a manufacturing change, not a new model, so the same model of AIO has two different AMD kits depending on when it was manufactured. I don't know if ASUS will supply the new kits for the older coolers, but the new kit can be purchased from Asetek via Amazon and isn't particularly expensive.
You should be safe enough to use the older AM4 kit on AM5 as either an interim or permanent solution, I believe, as long as good contact is being made with the CPU. Don't over-tighten the thumbscrew nuts.
When comparing the Asetek kits with the accessories supplied with the ROG AIOs, ignore the second mounting ring (the one without the ears, described as a "retention ring clip"), it's for older Asetek coolers as it's a universal kit.
Yeah, look at the standoffs and collars. The old AM4 version has a sort of collar on the board end that's permanently attached to the standoff; there's no separate collar. The new AM4/AM5 version has a typical double-ended standoff and a separate collar. The product photos on the Amazon listings should also make it quite obvious if you look at them side by side.
AM4/AM5 standoff & collar: