[SOLVED] Noctua nh-d15 runs like a vacuum cleaner on Gigabyte x570s.

Frostadamus

Commendable
Feb 14, 2019
6
1
1,510
I recently build a ryzen PC 5900x , gigabyte Aero x570s. I thought to get noctua cooler for cpu and shadow wings fans for the 4000d corsair case. (to have a silent build)
Unfortunately the cpu cooler feels like it goes to often on max speed. Tried setting from bios the PWM and the silent options, even made a fan curve... same results.
Even my old ryzen 1700 with no name coolers and overclocked is more silent.
Could anyone give some advice please?
 
Solution
Hello. I kinda fixed it.
In the noctua box there are 2x small extension cables(not the splitter) that seem to reduce the power of the 140mm fans.
I removed the splitter and added these small noise reduction extension cables. Added front 140mm into CPU_FAN, second 140mm into CPU_OPT.
Went to bios and set to CPU FAN AND CPU OPT - 25% PWM all the way to 50' celsius. 35% PWM to 60' - 55% PWM to 65' - and 75 + all the way to 100%.
After that max fan speed was 1159 RPM. Noise reduced significantly in full load and totally quiet while lightly using pc, also does not go anymore to 100% fan speed when you start PC.
Temperature in full stress went from 76' celsius previously to 78.5' currently.

Leaving this here in case someone else needs...
One thing to note, the latest Ryzen's boost algorithm is very sensitive. some software can cause frequencies and temperatures to spike very quickly even under light loads. This can make the fans spin up and down even at idle. I found Zen 2 a bit like this as well, I had to set a fan curve with a fairly high base temp to stop it doing this.
 

Frostadamus

Commendable
Feb 14, 2019
6
1
1,510
Hello. I kinda fixed it.
In the noctua box there are 2x small extension cables(not the splitter) that seem to reduce the power of the 140mm fans.
I removed the splitter and added these small noise reduction extension cables. Added front 140mm into CPU_FAN, second 140mm into CPU_OPT.
Went to bios and set to CPU FAN AND CPU OPT - 25% PWM all the way to 50' celsius. 35% PWM to 60' - 55% PWM to 65' - and 75 + all the way to 100%.
After that max fan speed was 1159 RPM. Noise reduced significantly in full load and totally quiet while lightly using pc, also does not go anymore to 100% fan speed when you start PC.
Temperature in full stress went from 76' celsius previously to 78.5' currently.

Leaving this here in case someone else needs.

Thank you.
 
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Solution

Paperdoc

Polypheme
Ambassador
What you did achieved your main goal - less noise. BUT it really caused a problem with your REAL problem - inadequate CPU cooling.

The "noise reduction extension cables" you installed are small resistors that slow down the fans by reducing the voltage to them. Of course that makes them quieter, BUT it also significantly reduces the air flow (and hence cooling) they can provide. Now, IF you do this and still allow the mobo CPU_FAN headers to do automatic control based on actual internal temperature in the CPU chip, that control system will just try to speed up the fans to get the air flow it needs. BUT by the time it gets to sending max power to the fans it can do no more, because you have limited the fans to LESS than the max power being sent out! So the CPU is now running hotter, that CPU_FAN header is trying to get max cooling, but your fans actually are running slower and quieter.

You should NOT use those Low Noise Adapter units supplied by Noctua when using the fans on a automatic control system. They merely limit the max cooling you can get.

Your real problem is that, even with max fan speed and NO LNA's installed, your CPU temp was still running on the high side. And yes, 1470 RPM is max - those fans are spec'd for 1500 RPM max. So WHY is that cooler system at max fan speed NOT giving you more cooling that the CPU needs? That's the question to answer. When you get it to cool as designed, it will slow down and get quieter.

One item to check. The cooler has two fans. They both must blow in the SAME direction. They can NOT be mounted, say, to have both blow INTO the cooler unit from two directions.