Just want to add to this post and hopefully get some advice.
I've had similar experinces as the op. I recently install a 3080 FE into my system and have noticed the temps of my 5900x are high. I saw it around 80c at one point until I went into the case (be Quiet Dark base 900) and moved the fans on the AIO.
AIO was top mounted on the case and I had the fans originally set to pull. Changed this to push and temps dropped by about 4c to around 76 but still creep up close to 80c.
The AIO I use is the Corsair H110i. Is it worth upgradding to a Artic Freezer II 280? Will there be much difference?
@greggo87 What kind of temp difference did you see in frnt mounting you AIO over top mounting??