NH-D15s Fan maxing out at ~1350 RPM

[fastfishy2]

Apparently the fan Noctua includes with the NH-D15S is specced at around 1500RPM +/-10%. Even with a certain temp threshold set for 100% load, mine will still only hit around 1350, which is technically within that 10% margin but it's right at the lower end. Not sure whether to be concerned or not.

[WereCat]

Does it cool well enough? 

I mean, if yes then enjoy lower noise levels. 

[fastfishy2]

Just now, WereCat said:

Does it cool well enough? 

I mean, if yes then enjoy lower noise levels. 

It does, I just wanted it to go a bit faster at the upper temp ranges. Weirdest thing is, it doesn't have this problem if I manually play with fan speeds in bios - it'll hit around 1420 RPM when commanded to go full load, which makes me think the MB might be paying attention to a different temp monitor.

[filpo]

4 minutes ago, fastfishy2 said:

Apparently the fan Noctua includes with the NH-D15S is specced at around 1500RPM +/-10%. Even with a certain temp threshold set for 100% load, mine will still only hit around 1350, which is technically within that 10% margin but it's right at the lower end. Not sure whether to be concerned or not.

No need to be concerned. Its a bit like the silicon lottery 

[fastfishy2]

1 minute ago, filpo said:

No need to be concerned. Its a bit like the silicon lottery 

ok so it seems to be a sensor discrepancy or some quirk of the bios - if the CPU hits 90c (i.e. prime95) the fan will ramp right up to absolute maximum and read around 1420 rpm.

[filpo]

2 minutes ago, fastfishy2 said:

ok so it seems to be a sensor discrepancy or some quirk of the bios - if the CPU hits 90c (i.e. prime95) the fan will ramp right up to absolute maximum and read around 1420 rpm.

Then how low does the cpu temp go? (also what cpu is it?) 

[fastfishy2]

9 minutes ago, filpo said:

Then how low does the cpu temp go? (also what cpu is it?) 

CPU is a 5800X3D and idles at around 37c with an ambient temp of 22c, currently I have the fan set to about 40% load at low temps which it is keeping to (650RPM ish)

[filpo]

1 minute ago, fastfishy2 said:

CPU is a 5800X3D and idles at around 37c with an ambient temp of 22c, currently I have the fan set to about 40% load at low temps which it is keeping to (650RPM ish)

I meant under load, try a cinebench run and check the temps. I would expect it to be around 80 or less with a spike at the start

[fastfishy2]

4 minutes ago, filpo said:

I meant under load, try a cinebench run and check the temps. I would expect it to be around 80 or less with a spike at the start

Ok so, there's a lot going on here.

I ran HWinfo64 for the first time in ages and realised that the temps reported by OCCT and Ryzen master are CPU package temp, whilst there is a separate temperature for the CPU core itself which is around 10c lower. This explains the strange fan curve behaviour as the motherboard is likely reading CPU core temp whilst I've been looking at package temp the entire time.

[TeraSeraph]

80 RPM off maximum when on an impedance is a little abnormal for Noctua but nothing to worry about. Usually they maintain or exceed their rated RPM in most situations, this might be a rare case where the fan is a little slower.

[RevGAM]

3 hours ago, fastfishy2 said:

It does, I just wanted it to go a bit faster at the upper temp ranges. Weirdest thing is, it doesn't have this problem if I manually play with fan speeds in bios - it'll hit around 1420 RPM when commanded to go full load, which makes me think the MB might be paying attention to a different temp monitor.

That is likely correct. Disable mobo fan control software and test. 

 

Also, check and modify fan curves in BIOS and software. 

 

FYI, BIOS generally uses 2 sensors for the fan curve: CPU (lower) and CPU package (upper).

[fastfishy2]

6 hours ago, RevGAM said:

That is likely correct. Disable mobo fan control software and test. 

 

Also, check and modify fan curves in BIOS and software. 

 

FYI, BIOS generally uses 2 sensors for the fan curve: CPU (lower) and CPU package (upper).

I can confirm from setting the mobo max cpu fan ramp temperature lower, and monitoring package and core, the mobo is taking its cpu fan speed cues from CPU, not package. I'll just have to account for that in my fan curve.

[RevGAM]

31 minutes ago, fastfishy2 said:

I can confirm from setting the mobo max cpu fan ramp temperature lower, and monitoring package and core, the mobo is taking its cpu fan speed cues from CPU, not package. I'll just have to account for that in my fan curve.

I'm glad my info was useful!