Optimizing the M3 for Thermals

Hello everyone. I am currently working on a build in the M3. I discovered the case when looking into the SFF community, and the M3 feels perfect for me. It’s small and built with high quality materials, allowing me to travel and keep it in cramped environments, but flexible enough to fit any parts I need for the most part. I’m using it as an all-purpose rig with some recording and writing, but the most intensive thing I’ll be using it for is gaming.

However, I have grown a bit nervous regarding the thermals. My understanding is that a reversed build with the GPU at the top is optimal for GPU thermals, but my card is very big, and I’d prefer not to have an upside-down build. I was going to use an Arctic Liquid Freezer III 280, as it seems to have the best performance amongst AIOs, but due to my motherboard (ROG STRIX x870-I) the giant M.2 heatsink makes it incompatible. I also considered air cooling with the NH-D15 but that is incompatible for similar reasons.

If anyone has any advice for optimizing thermals it would be greatly appreciated. I am considering replacing the motherboard, but it seems to be the best option (and has a lot of good ports which is good for me). This is my second PC build and first SFF build, so I’m just a bit nervous about the thermals. I’m trying to get the best performance out of my rig and really don’t want to overheat the thing.

Here are my parts for the time-being, though I am considering replacing some of them as needs be:

Motherboard: Asus ROG Strix x870-I
PSU: Corsair SF-1000
GPU: Asus ROG Astral 5080
CPU: Ryzen 7 9850x3d