1. Did you try out the Corsair ML120 Pro? It makes a lower frequency hum compared to Noctua fans.

2. If your rig is liquid cooled, see if the high pitch sound is due to the pump. I have a slight buzzing sound from my R8 nowadays after I got rid of fan noise and now the pump sound is audible.

You can disconnect the fan header one by one while system is on to see which fan causes the issue. Sometimes it could be that you're just able to hear the sound and it bothers you especially when the room is very quiet.

I have tried different things, installed 3 BIOS updates since I noticed the crazy fan noise, have tried two other front fans. And since I won`t go into further modding  I have come to terms with fan noise and accepted the noise coming from my replacement noctua nf a12x25 pwm front fan.

So, here is my conclusion and what I have learned about the Aurora R8 I use (I9 9900K liquid cooled, RTX 2080 ti):

1. The crazy fan noise is coming from the front fan when CPU temps go above 80°C
2. Dell has mitigated this crazy fan response in BIOS 1.07, still front fan behavior and noise is not “normal”
3. You can fix speeds or do a curve in AWCC and the fan will obey unless the CPU temps go into the danger zone (above 80°C) at which a “safety” BIOS config takes over and overrides AWCC.
4. The temp probes of the Top and Front fan seem to be really close because they almost always indicate the same temps. This actually is the big problem here because:
5. …the front fan will not really participate in CPU cooling since the RTX 2080ti basically divides the R8 case into two almost enclosed and separated compartments.
6. The Front Fan does only feed the lower compartment below the graphic card blowing fresh air to the suctioning fan of the RTX 2080ti
7. So why is it that front fan RPM increase when CPU temps go up? Because high CPU temps are immediately reflected by Top and Front Fan temps (indicating same temps) which lets both fans rev up but only the front fan is producing that horrendous sound for nothing since it won`t cool the CPU/radiator in any way. It just blows below the graphic card.
8. So, it would make sense to have the Front Fan under the control of the graphic card either directly or indirectly by placing the Front Fan temp probe onto the 2080ti.
9. Increasing airflow towards the GPU fan due to increased Front Fan RPM does make a difference in GPU temps of 2-3 °C. Doing a 3dmark stress test with Front Fan on Auto will leave it at idle speeds of 400-500 RPM (because CPU workload is around 20-30% thus low CPU temps) resulting in GPU temps of 84-85°C. Manually maxing Front Fan speed (for instance 2000 RPM nf a 12x25) results in max GPU temps of 81-82°C.
10. For the nf a 12x25 I have found that at around 1200 RPM the noise of the fan is acceptable (2000 RPM is way too loud) and does not let GPU temps rise above 83°C in 3dmark stress test. However, if the GPU is stressed to above 80°C the GPU Fan goes above 3000 RPM which then is by far the noisiest thing in my R8 easily overshadowing 2000 RPM of the nf a 12x25. So, GPU controlled Front Fan still the most sensible thing to do.

Finally a short question, which has nothing to do with crazy fan noise.  Anyone noticed that the RTX 2080ti blows its hot air straight onto the HDMI cable(s)? I am not sure but hot air of 80°C and more for more than 1h will cook those cables, won`t it? What is the temp limit of HDMI cables?

Keep the loud fans. They push a lot of air.  

Utilize the fan curve settings in AWCC. You’ll find a setting that fits your needs. 

@ Dell630i:

"If you are happy with the Noctua feeding air to your graphics card at 1200 RPM, the why not use the Noctua NF-S12A FLX 3-pin fan at 1200 RPM and 17.8 dB, so it does not rev up for no purpose when your CPU is hot."

The S12 is weak on static pressure and there is a lot of cramped space the front fan has to blow.  The A12 is much better at this. For instance, with the S12 running at max RPM I could not prevent the 2080ti from reaching 84°C in stress testing. Apart from that, I find the higher pitch noise the S12 running at max RPM is producing more annoying than the noise of the A12.

"Also consider a push-pull configuration for your CPU radiator; not for less noise, but for cooler CPU temps."

I doubt that this would help because CPU temps jump up from 40°C to above 80°C in an instance as soon as CPU voltages go up for increased workload. The Fans rev up accordingly. I already talked to Dell if this is normal behavior for a liquid cooled CPU and apparently it is for the 9900K.

@Bmwpower603 

"Utilize the fan curve settings in AWCC. You’ll find a setting that fits your needs."

This wont work because CPU temps wont rise slowly but initially spike (see also my last post to Dell603i) and these spikes make the fans go crazy. A gradual increase in RPM and noise is much easier to tolerate than 500RPM to 2000 in one second.

I doubt that this would help because CPU temps jump up from 40°C to above 80°C in an instance as soon as CPU voltages go up for increased workload. The Fans rev up accordingly. I already talked to Dell if this is normal behavior for a liquid cooled CPU and apparently it is for the 9900K.

I disagree. Please reach out to Intel to confirm this. Ramping supply voltage is controlled by CPU's embedded power microcontroller and this doesn't seem to be the behavior that is expected.

27C idle sounds about right with AIO liquid cooling.

Now let's get some basics in place:

For AIO solution, you need to "satisfy" 2 headers on your board or BIOS throws you an error. Do this:

CPU_PUMP - AIO pump

TOP_FAN - AIO fan

Do not plug anything into CPU_FAN. The other thing is, there are only 3 types of fans that won't cause an error when plugged into TOP_FAN:

1. Dell's stock AIO cooler fan.

2. Corsair ML120 Pro.

3. Any non-PWM/ constant speed fan.

If you are going the sandwich route with 2x ML120 Pros, you should be using a y-split cable to drive both fans using TOP_FAN header. Your FRONT_FAN header should still be connected to the front fan that came with your R8. If you want to get rid of stock fan noise, I suggest you either get another ML120 Pro/ Noctua AF12x25 PWM or use single ML120 Pro at the top, and place the other ML120 Pro in front. Make sense?

My personal choice would be that you go with the latter because:

1. You mentioned 9900 which means you won't be able to overclock. Hence 1x fan should suffice even under load.

2. It's a pain trying to squeeze in the 2 fans. I seriously thought I took out a capacitor or VRM when wresting the entire sandwich back in place!

Really interesting Read. thanks everyone.

I also got a cheap! outlet R8 with i9 9900, RTX 2080, 32GB hyperX RAM, 1TB NVME for ~£1500 scratch and dent.

I turned it on and almost cried. Since then i have purchased the Intel BXTS13X AIO thermal solution as "suggested" https://www.dell.com/community/Alienware-Desktops/Aurora-R8-Intel-BXTS13X-Water-Liquid-Cooling/td-p/7288180 And https://www.intel.co.uk/content/www/uk/en/support/articles/000031328/processors/intel-core-processors.html.

Noise and temperatures have dropped significantly.  Temps were previously 55C but now 27C in idle. Does that seem ok for an AIO?

I now get the BIOS Fan error 2000-0511 on startup but after a couple of minutes can log in fine. I have 2 ML 120 Pros arriving tomorrow which I hope will fix the issue.

Has anyone else used the BXTS13X? If so did you find it only works off the CPU header as the combined fan uses inline power supply? (PC wouldn't boot at all if i plugged it in to top or pump headers).

I am hoping that in "PushMePullYou" mode with one of the ML120Pro fans doing the pull part of the sandwich plugged into the top fan header. and the second ML120Pro fan in the front position i will bypass the bios b***locks. (Fix the noise and reduce the temps as well :-))

@GTS81 Thanks

I have followed your suggestions and removed pump fan and put original top stock fan in its place.

I have just rebooted a couple of times with only pump in pump header, original stock fan in "Top" header mounted on radiator (Only 2 screws as corsairs arrive tomorrow). I am still getting the bios complain (2000-0511) about CPU Fan.

With the original stock fan inline so both pump and fan are on CPU_FAN. I dont get the bios error about CPU FAN.

But............

I am getting the 2000-0511 error for TOP_FAN now! 

Idle temps are now in the mid 30Cs (could be because case is open while i do these tests)

I will wait until tomorrow and put the PushMePullYou in with both corsairs one in Line to CPU_FAN with Pump and one into top fan.

If that doesnt work i will return the BXTS13X and get the Corsair H60 as others in the community appear to be working on that.

@Whinjinpom , I apologize. Looks like @HanoverB has written about the correct way to hook up this AIO before:

https://www.dell.com/community/XPS-Desktops/XPS-8930-alternative-cooling-solution-8700k-delid/m-p/7326495/highlight/true#M25326

So both your pump and fan needs to be powered by CPU_FAN and then another fan by TOP_FAN? I'm not sure why this Intel pump is special. With Dell's AIO pump + Corsair ML120 Pro, I have no error with CPU_PUMP and TOP_FAN. 

Looking forward to hearing from your test with the ML120 Pros. As far as I know, the only difference between your system and mine would be the AIO pump + radiator.

We are glad to hear the issue has been fixed after replacing the top fan, in case further assistance is required with your system feel free to send us a private message. Have a great weekend  

@GTS81 so Corsair ML 120 Pro fans have arrived and have them setup in pushmepullyou setup plugged in to TOP_FAN and both Pump AIO and fan into CPU_FAN headers.

No BIOS Moaning now

using HWINFO64 to monitor temps and fans and all look good.

One thing with the setup is that with radio further in to the case with the fan sandwich they do get a little squashed by PSU door.

I realised this so carefully pushed the tube back while shutting the door to stop them getting pinched. I also put a bit of PVC tape over the edge of the PSU door to stop the edge scraping the tubes.

all connectedpump tubes about to get squishedPVC tape on the curved but rigid edgeholding the tube back while closing the PSU

I now need a third fan fro the front to complete next month hopefully.

(PS i also removed surplus disk caddy and cables from the case to try and make airflow as clear as possible).