Ok probably not all you're hoping for, but I did SOME testing using the 3080 FE. All my testing was done using Minecraft RTX mind you; the game I really wanted to try ;-), but obviously not the most heavy hitter. I ran into some serious noise issues; not the acoustic performance I was hoping for or expecting. MUCH worse than my previous 1080. I immediately tried some undervolting hoping for some relief, using
these exact settings. Stable for sure (in Minecraft lol), but the noise still ramped up. Looked at my temps and fan speed; around 69 degrees Celsius and 40% fan speed. GPU fan speed did not ramp up but the noise got much worse. Turns out to be quite obvious: the PSU was ramping up its fan unlike I've ever seen. I figured "there's a couple mm space for the hot air to get out, so let's turn that 3080 back around". And so I did. Much better. MUCH. GPU temps and fan speed APPEAR to be roughly the same, but while the PSU noise started after about 10 minutes when using the PSU as an exhaust, things are now still reasonably quiet after almost an hour. I can feel the cool air being drawn by the PSU, and the top of the case is much less hot to the touch than before. Still a bit more noise than the 1080 FE, but this was to be expected and overall seems reasonable to me. During this testing I did not revert the undervolting, I'm going to keep it this way and see if it's stable. Honestly, I'm happy with the performance now, maybe I'll even put the plastic sheet back in.
TLDR: I do
not recommend flipping the PSU to serve as an exhaust myself. Thermal performance
seems okay with the PSU drawing in fresh air, though testing was rather limited.
FYI: the PSU is a Corsair SF600, and in the case is a 8700K (stock clocks) as well being cooled using a Noctua NH-L9i.