N5105 generic box, very high temperature

[chuliu]

I am running opnsense on the n5105 generic box which I bought on aliexpress.
It was working fine with my two ftth, 1gb and 2.5gb respectively until I accidentally noticed that cpu temperature was very high at 81 celcius degrees.  I shut it down immediately.

I have a friend who also owns a box with similar hardware and he is running vyos.
The cpu temperature is around 65 celcius according to him.

I didn't feel the cpu was throttled due to overheating, but I did notice the case was very hot.

Is there any way I can reduce the cpu temperature?  I don't want to replace it or change to other os, since it was working fine.

[newsense]

Check out Patrick's videos and Serve the Home forums about your issue, you may have to open the box and make sure the CPU is in contact with the case for proper cooling.

There's nothing to be done on the software side - unless you can see some process pegging the CPU to 100% - but even so you shouldn't reach 81C easily...

[chuliu]

Hi,
My powerd settings are on and hiadaptive for all three options.
I have enter bios and changed cpu pl1 and pl2 to 10 and 12 following the advice from the other thread.
The cpu temperature is now at around 70 degrees.

I will apply new thermal conductivity tonight and keep you posted about the cpu temperature.

[meyergru]

Sometimes, in addition to the abysmal contact between CPU and case, the PL1 setting in the BIOS is a little on the high side, too. My topton unit took 27 Watts despite the N5105 having a TDP of only 10 Watts. Passive cooling is not too good at dissipating more than ~20 Watts.

However, if your CPU gets hot even when idling, the contact patch is the culprit. Also, do look at the machining of the screw holes where the heatsink was attached to the case. I found a ridge on the edge of the holes, they forgot to bone them. No amount of thermal paste could have fixed that.

See https://www.congenio.de/infos/opnsense-hardware.html

[chuliu]

After I re-applied cpu thermal paste, along with changing pl1 and pl2 in bios to 10w and 12w, the temperature stays between 50 and 52 degrees.

[vollans]

I moved over to OPNSense, after using pfSense for a long while, and I hit the same problem which I also initially hit with recent releases of pfSense. The N5105 doesn't play nicely with "modern" power saving, so you have to forcibly disable that and tell it to use old fashioned PowerD power management instead.

In the /boot/loader.conf.local file add:

hint.hwpstate_intel.0.disabled=1

And reboot. Mine dropped from high 80sC to 40s after rebooting.

[chuliu]

The cpu temperature has been staying in the range of 62 to 63 Celsius recently.  I did add that line to the /boot/loader.local file and it seems to reduce further 3 degrees to 59 degrees.

[36thchamber]

if you buy newer revisions of the boxes mentioned in STH, with those juicy CPUs like N100,N300,Gold8505, they will have a great build. They will typically have 3 series of holes in the bottom. Great paste applied. Ultra stable. I am at 40℃ idle but I go to 100℃ when busy easily. Can't care less, all modern CPUs  throttle based on temperature. You can cool it down faster by adding 80x80x10 internal fan in the bottom, or 14x14x16 usb fan on the top. The top fan is much more efficient, it will drag temperature down under room temperature despite ultra thin even at 5volts.

[passeri]

14x14? That is a pretty tiny fan. Was that 140x140 mm?

I had a device whose case was warmer than I wanted (no actual problem) so I experimented with a 40 mm USB fan blowing across the fins, running at the minimum of its three speeds. It was very effective at dragging down temperature. Steady airflow does not need to be fast, as you can find by researching heatsinks with and without active airflow. Placing the fan on top is also very effective but tends to be a little noisier.

The big virtue of fan-over-fins compared with a fan in the case is that the case is not gradually filled with dust, thus preserving one of the original virtues of passive cooling.

[36thchamber]

14x14? That is a pretty tiny fan. Was that 140x140 mm?

oops, 140x140x16, aligned with the box size. Artic slim version, dead quiet @5V, direct USB @5V or 12V with the USB-to-fan adapter. Yes the top placement is much more effective and almost invisible. So I could place it anywhere. Without it, the whole box was hard to touch. The bottom 80x80x10 doesn't reduce box temperature at all, but it does cool internal components such as NVME, Wifi 6E etc as i've monitored in s-tui app. I second your experience.

[Seimus]

14x14? That is a pretty tiny fan. Was that 140x140 mm?

oops, 140x140x16, aligned with the box size. Artic slim version, dead quiet @5V, direct USB @5V or 12V with the USB-to-fan adapter. Yes the top placement is much more effective and almost invisible. So I could place it anywhere. Without it, the whole box was hard to touch. The bottom 80x80x10 doesn't reduce box temperature at all, but it does cool internal components such as NVME, Wifi 6E etc as i've monitored in s-tui app. I second your experience.

Thank you for the FAN suggestion I was looking for a good low profile FAN. Bought this one, and can see benefits already.



Regards,
S.

[Patrick M. Hausen]

In the /boot/loader.conf.local file add:

hint.hwpstate_intel.0.disabled=1

Why don't you use the UI for that?