Good morning guys, thank you all for the responses, I spent whole yesterday and this morning doing test, tilting and doing stress testes. Before we go any further here's a quick recap of my liquid cooled components:
CPU: 9900K at stock with ekwb
GPU: 3080 Ti FTW3 at stock with ekwb
Motherboard: Aorus Master Z390
2 radiator 360 PE series and a ekwb vtx pump.
Here's a photo of the system with a lookup of the cpu and gpu fins in detail:
Lets' start from yesterday with this situation at boot with a thermal probe directly inside pump reservoir and thermohygrometer next to it for room temp readings:
So coolant temp at boot 27°C, with room temp 27 °C throughout the entire test.
And after closing the case and wait the temps to normalize they were like this:
with GPU temp the same as coolant temp.
I started some stress right away and at the end of it here's the situation:
Max gpu temp around 70/71 °C and I would like to point out that pump speed was between 3200 and 4200 rpm depending on the load.
Now we are at this morning. Following the suggestion of trying to make escape some air bubble trapped inside the system I tilted the system even 180° in both axis and made the pump run and indeed some air bubbles manage to escape from the top radiator.
This morning we have 30 °C instead and the stress tests were performed with the case opened:
Coolant temp 31°C, room temp 29°C (it will be 30°C in some minutes) and after some times the system idling like this:
Ran 3 stress tests and these are the results:
so max gpu temp around 67/68 °C with coolant temperature like this:
So a quick recap for the maximum values:
Close case - gpu temp around 70 °C, coolant temp 45°C and 27 °C room temp.
Open Case - gpu temp around 67 °C, coolant temp 44°C and 30 °C room temp.
I hope I explained everything. Do let me know if you need something else. In the meantime I will try to switch fan orientation and see if I make some progress.
I will keep you up to date and thank again for your help :D