https://smallformfactor.net/forum/threads/gamersnexus-would-this-be-the-correct-orientation.14788/
Asetek - AseDen:
Sorry for being lazy and not realizing this post was here. My bad! Thought I had enabled email notifications 🤪
I'm one of his sources for information on why AIO orientation matters.
That being said, I think that there's a level of "drama" added to the content piece (and obviously the title) - but it's probably needed to drive clicks. That being said, there are of course merits to the claims made. Having the "wrong" orientation won't kill your AIO for any forseeable future unless it was constructed horribly and/or without sense of Quality & Control.
You are however likely to experience "gurgling" as I'm sure most SFF builders are aware of. It's not damaging (in any real or measurable way) unless you get to a point where evaporation through the tubes has allowed the pump to run completely dry (or maybe use a manufacturer that leaves 10% air in there - nearly choked on my coffee, there 😨).
I would assume this mostly relates to the 645LT.
As I've mentioned on here a few times, it's fine to run it in its natural position in the Dan-Cases A4-SFX. Absolutely fine! You may experience the pump gurgling - because it's vertically above the radiator/hex. Now, there's a relatively easy (as if anything is easy in SFF, lol!) fix, which is flipping the rad 180 degrees, having tubes at the bottom of the case. This will allow air bubbles to stick in the rad/hex rather than the pump/block combo.
As always, happy to discuss further and/or get more in-depth