Recommendations for CPU fan curves

[Megaman]

I'm using iCue to adjust fan curves on my 360mm 150i XT Pro. I have changed the sensor away from the pump coolant temp and have gone with CPU package instead. Below is a quick setup curve I'm going with for now.

Any reason I should not move away from pump coolant temp?

What curves are ya'll using?

[demo]

Mine is set to balanced and based on coolant temp, primarily because I disabled icue startup and coolant temp is default and reads and displays on lcd screen correctly without icue software running. Seems to work just fine - there was no real performance difference between fan curve based on coolant temp or CPU package. If anything coolant temp changes fan speed more gradually because temps aren't jumping up and down like CPU package, resulting in less intrusive fan speed changes/noise.

[Megaman]

Originally Posted by demo

If anything coolant temp changes fan speed more gradually because temps aren't jumping up and down like CPU package, resulting in less intrusive fan speed changes/noise.

Good point, I didn't think about the fluctuations in fan speeds that would come about using the CPU package. I have always used coolant temp as the sensor, thought maybe I could drop a few degrees with a custom curve.

I also never had any visual on what the graphs looked like on quiet and balanced mode until now. I found the graph curves for these within the custom cooling preset, something I have overlooked all this time.

I'll revert the curves back to balanced. Thanks

[KAC]

I don’t do fan curves as I hate ramp up or ramp down of fans. Since I am using Arctic and Noctua fans I set fans to custom 1400 RPM and pump to balanced 2200 rpm. Is pretty inaudible.

Fan curves are for pussies.

[andino]

I almost always set the curves to coolant temps.

What most people don't get is that you are cooling the liquid in the loop not the CPU/GPU. Now if the fans were directly cooling the CPU/GPU then it's different. You set the fan speeds to the CPU/GPU temp.

With an AIO or any loop, you are passing cool liquid past the thing you want to cool. So, your main focus should be cooling the coolant. Therefore, the temp in the loop should set the fan curves...

[Hapatingjaky]

Just set extreme like KAC and never look back.

I'm a poet and don't even know it.

[KAC]

[Sasquach]

if the curve is the shape of a boob,
you are doing it right.

[metroidfox]

Originally Posted by Sasquach

if the curve is the shape of a boob,
you are doing it right.

[acroig]

Originally Posted by Sasquach

if the curve is the shape of a boob,
you are doing it right.

I approve this message.

[Megaman]

OK so moving on to the 4 exhaust fans I have at the rear/top of the case and for my setup where the CPU cooler is front mounted, i.e hot air being dumped into the case, the fans work of CPU package. I was thinking maybe those should be set on GPU temp however iCue has only 3 GPU sensors, NV 3080 temp 1/2/3.

Is CPU package optimal with a custom curve?

[Nunz]

Coolant temp.

[Nagorak]

So, the thing about CPU fan curves is that a lot of times running the fans faster is unnecessary/doesn't really help. With the small die size of modern CPUs oftentimes the transfer bottleneck is between the CPU die and the cooler/waterblock. Then your cooler also may only transfer heat so easily to the air, so there are diminishing returns on how much extra airflow helps there either. As a result, oftentimes turning your fans up to to 100%, or even replacing with an extreme 3000 RPM version, doesn't make a difference of more than a degree or two. With GPU's having a larger die heat transfer isn't as much of an issue there, but even so excessive fan speed/noise may not end up doing that much for you.

With a watercooled system, I think an argument can be made to ramp the CPU fans based on coolant temp. However, you do encounter the problem that ambient temperature can play a big role in what your coolant temp is. So, a nice quite curve in the winter can be unnecessarily loud in the summer, depending on how you set it up.

Personally if you're running off CPU temp I'd say set the fans to be relatively low RPM all the way through 70 or 75 degrees (exact percentage depends on overall max fan speed; if it's 2000 RPM then maybe run 50% at 70 to 75), then ramp up more aggressively, with maybe hitting 100% at 85 or 90 degrees or something. The extra fan speed probably won't help you that much at those high temps either, but that should only happen during stress testing and it doesn't hurt to throw everything you have at in that case.

[Nagorak]

Regarding case fans, if your software can only handle one temperature source, then you basically have to decide which to follow. I think an argument can be made for setting based on GPU temp, considering the GPU usually ends up putting out more heat since it draws the most power (at least when gaming).

There are some software fan control programs, like Argus Monitor, where you can set fan curves based on multiple sensors. I use Argus Monitor myself for all my systems and highly recommend it.

Another option may be to swap the CPU radiator to the top position and use it as exhaust, in which case you don't have to worry about the CPU heating up the case at all, and can just rely on GPU temperatures.

I would probably tune your fan curve for the GPU temp. Then the real key is to try to match the volume of your fans. Basically, there's no point running a case fan at low RPM if you can't hear it over your screaming GPU fan. So, you just pick a target noise level and temperature level, and then adjust the fans until they all are about the same volume at a given temperature. Once you have the basic curves locked in, you can then adjust up or down depending on whether you want lower temps or quieter system.

As for which GPU sensor to go with, I'd load up a game along with MSI Afterburner and see if you can identify which sensor is which. One of them is probably core average, one is probably hot spot, and the third might be memory temperature. Probably average core temp or hot spot make the most sense to use.