Too many fans?

[Pablosammy]

for the resonance try dropping or raising the rpm on the fans bit by bit. it You should be able to pick up the point where it quietens down. Just set your fan curve with a step that passes that rpm

It's odd, there's no particular resonant frequency, the noise is proportional to the fan speed. Maybe it isn't strictly resonance, but there is some interaction going on. More playing required.

 

[ttaskmaster]

I don't really want to fit external fans for aesthetic reasons. I think you're right about the grill being part the issue, but the grill itself isn't vibrating.

No, the resonance is usually the exhaust airflow hitting the grille and being baffled, which is why it changes with fan speed (and thus changing airflow). This is further exacerbated by the second conflicting airflows from the other fans around it.
Another option is to cut the grille completely out and just leave the mounting points.

 

[MATT4CK]

I've found that sometimes it's the fan itself that's making the noise. Not that it's causing resonance. I've had some (admittedly not Noctua) that really don't like one certain orientation.
It can even be 2 fans of the same model and one doesn't like being inverted and the other doesn't care.
Is there any spots for fan mounting under the PSU shroud? It looks to have ventilation holes

 

[Blackjack Davy]

Hi all,

I'm moving back to air cooling, and wanted to run the above set up by you. I had a load of 140mm Noctuas from past builds and thought I might as well max out the cooling space, but I'm a bit worried it'll be self defeating.

That's a 3090 FE and a Noctua D15, which both dwarf the case.

There's two Noctua A14s at the front set as intake - one is directed underneath the GPU to feed the two fans, and the other is aimed at the CPU cooler. I'm hoping the exhaust from the GPU won't affect the CPU cooler too much.

The exhaust are 3 P14s. My main worry was about the top two exhaust fans. The left one doesn't look like it'll be doing much, and the right one could end up just exhausting cold air from the intake that could have gone through the cooler. Would you set the right one as intake? Or just not have them at all?

Obviously I'll experiment a bit when it's up and running, but there's a lot of variables so I thought it would be better to draw on experience!

I think to be honest you're worrying a bit too much so long as you've got some forward->back->up airflow moving through the case thats all that matters really. I've no idea about resonance I've never heard of such a thing.

How are you finding the temperatures? I'm finding the 3090 dumps an awful lot of heat in the case no surprises there with the collosal power consumption and its totally overwhelmed my previous case fans/airflow setup the heat rising saturates the CPU and temperatures go through the roof I swapped out the air cooler with a liquid cooled AIO originally top mounted but that was no better due to the same heat so had to front fit the rad and swap the fans around to pull air in rather than exhaust it and that seems to have fixed it its gone from to 45/85c to 35/65c, much better. (Only trouble is had to ghetto mod the case to fit it in the front but oh well.)

 

[Pablosammy]

I think to be honest you're worrying a bit too much so long as you've got some forward->back->up airflow moving through the case thats all that matters really. I've no idea about resonance I've never heard of such a thing.

How are you finding the temperatures? I'm finding the 3090 dumps an awful lot of heat in the case no surprises there with the collosal power consumption and its totally overwhelmed my previous case fans/airflow setup the heat rising saturates the CPU and temperatures go through the roof I swapped out the air cooler with a liquid cooled AIO originally top mounted but that was no better due to the same heat so had to front fit the rad and swap the fans around to pull air in rather than exhaust it and that seems to have fixed it its gone from to 45/85c to 35/65c, much better. (Only trouble is had to ghetto mod the case to fit it in the front but oh well.)

The GPU temps are fine, it's quite efficient at removing it's own heat, but as you say it does warm the rest of the case fairly well! The GPU controls itself at 68 degrees under load whatever I do with airflow, the fan speed is the only thing that changes. Currently it maxes at 50%. I do have a mild undervolt though.

I've got my airflow fairly sorted now so it's staying relatively quiet and the CPU is okay, but as soon as a waterblock is released I'm going to do a custom loop.