Noob question about fan curves and issue with fan

[TristanN]

Hi,

 

I recently built a new PC:

 

3800XT

G.Skill Trident Z Neo 2x16GB 3600 CL16 RAM

MSI X570 Tomahawk

Noctua NH-D15 (using 1 fan)

970 Evo Plus

GTX 970

Phanteks SK140 DRG PWM Fan (Exhaust)

Phanteks P500A Case with 3x 3pin 140 Fans for Intake

 

I am not really sure how to set up the fan curves... 

 

Initially I just set everything on Smart Fan Mode, but the fans would constantly ramp up and down I guess due to the temp spikes which was very annoying. I then changed the step-up/step-down times but that didn't help much so tried creating my own fan curves. I also switched the temp source for the front intake fans to "system", I wanted to choose "MOS" but for some reason it won't let me choose that option.

 

With the custom fan curves, my CPU is around 35C Idle, around 45-55C while gaming, and when testing with Cinebench gets up to 78C on multi and 60C on single core test. I'm a complete noob but those temps sound ok right?

 

 

This is what I have for the CPU/Exhaust Fan (Both PWM and Temp Source set to "CPU"): 0C/50% 40C/50% 65C/75% 70C/100%

 

 

 

This is what I have for the Intake Fans (3pin DC Fans): 40C/8.40V 55C/9.00V 70C/10.80V 75C/12.00V

 

 

 

Are those fan curves ok?

 

Also, any idea why System Fan 2 keeps jumping between 0 RPM and 2000+RPM? It's the only fan that does that. The other intake fans stay around 1000 RPM most of the time, using "system" as temp source doesn't seem to change their speed much. 

 

Ambient temperature is 24.5C.

 

 

Thanks a lot for your help!

[narrdarr]

It happens because of cpu spikes. During the spike the temp jumps up for just a second and comes back down and the fan fallows. You can combat this in to ways.

 

1. Set you can curve base higher than the spike. 

 

Or

2. Set a time delay to the fans responsiveness. The bios usually doesn't have this feature. But the motherboard utility should or you can try using another software to do this like fancontrol

[TristanN]

Yeah sorry, I no longer have the fan ramping up/down quickly, I just wanted to make sure the fan curves and temps are alright.

[LogicalDrm]

On 9/9/2020 at 2:54 PM, TristanN said:

Yeah sorry, I no longer have the fan ramping up/down quickly, I just wanted to make sure the fan curves and temps are alright.

There's no "right" or "wrong" way to setup fan curves. They are really representation of what you like and want. Temps are relative to stress, CPU, voltage and so on. Without knowing what CPU voltage was under stress testing, its hard to say anything about it. 78C is higher than what it should be. Cinebench is not that heavy. But then again, if you have PBO set to auto, that might be contributing.

 

With curves, you are selecting between two options. Temps and noise. Nothing else really. Less noise means higher temps are you are setting fan speed slower. CPUs (everything Intel and AMD Ryzen) are fine up to 80C+ under full stress load. Each person has their own preferenced there too, mine is 87C under full stress testing. GPUs are fine to 85C, my own gaming temp is 80C because of too high fan noises.

[TristanN]

19 hours ago, LogicalDrm said:

There's no "right" or "wrong" way to setup fan curves. They are really representation of what you like and want. Temps are relative to stress, CPU, voltage and so on. Without knowing what CPU voltage was under stress testing, its hard to say anything about it. 78C is higher than what it should be. Cinebench is not that heavy. But then again, if you have PBO set to auto, that might be contributing.

 

With curves, you are selecting between two options. Temps and noise. Nothing else really. Less noise means higher temps are you are setting fan speed slower. CPUs (everything Intel and AMD Ryzen) are fine up to 80C+ under full stress load. Each person has their own preferenced there too, mine is 87C under full stress testing. GPUs are fine to 85C, my own gaming temp is 80C because of too high fan noises.

Thanks for the input. Looking at Ryzen Master, the voltage is 1.375V during cinebench r20, cpu runs at 4,280 MHz. Everything is stock except for XMP turned on. 78C is the highest I've seen, it's usually 73-75C. I found a thread were people listed their ryzen temps during cinenbench, and based on that 70-80C seems normal.

 

I guess like you said with fan curves it comes down to preference, so will just make sure cpu stays under 80C. Will increase fans a bit, don't really mind the noise since I use the pc mostly for gaming, it was just the ramping up/down which was bothering me but the fan curve solved that.

 

Thanks again