Very high temps when idle

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1

I have an Intel NUC pc, used as media player. Since its power consumption is very low, I tend to have it online 24/7.
However, the other day, when I was cleaning, I touched it and it was very hot!!
I logged in, and noticed that it was reaching temps around 100C (all 4 cores)

At first I checked htop, but nothing was occupying CPUs other than normal tasks and the higher CPU% usage was around 8% from “kwin_x11”.

I installed PSensor to log what is going on, and I realized that the temps are sky high when it is idle and as soon as I login (local or remotely with nomachine) they fall to around 70C (still high, but keep in mind there is no airflow, it has passive cooling).

inxi -F

System:
  Host: manjaro-media-pc Kernel: 6.6.47-1-MANJARO arch: x86_64 bits: 64
  Desktop: KDE Plasma v: 6.0.5 Distro: Manjaro Linux
Machine:
  Type: Mini-pc System: Fanless Mini PC product: Quieter 3 v: N/A
    serial: <superuser required>
  Mobo: Fanless Mini PC model: Rev JSL1 1.10 serial: <superuser required>
    UEFI: American Megatrends LLC. v: ML_JPL1V1.0 date: 03/15/2022
CPU:
  Info: quad core model: Intel Celeron N5105 bits: 64 type: MCP cache:
    L2: 1.5 MiB
  Speed (MHz): avg: 2800 min/max: 800/2900 cores: 1: 2800 2: 2800 3: 2800
    4: 2800
Graphics:
  Device-1: Intel JasperLake [UHD Graphics] driver: i915 v: kernel
  Display: x11 server: X.Org v: 21.1.13 with: Xwayland v: 24.1.2 driver: X:
    loaded: modesetting dri: iris gpu: i915 s-res: 3840x2160
    resolution: 3840x2160
  API: EGL v: 1.5 drivers: iris,swrast platforms: gbm,x11,surfaceless,device
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa v: 24.1.6-arch1.1
    renderer: Mesa Intel UHD Graphics (JSL)
  API: Vulkan v: 1.3.279 drivers: intel surfaces: xcb,xlib
Audio:
  Device-1: Intel Jasper Lake HD Audio driver: snd_hda_intel
  API: ALSA v: k6.6.47-1-MANJARO status: kernel-api
  Server-1: PipeWire v: 1.2.3 status: active
Network:
  Device-1: Intel Wi-Fi 6 AX201 160MHz driver: iwlwifi
  IF: wlp0s20f3 state: down mac: 82:1f:2c:5c:da:72
  Device-2: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
    driver: r8169
  IF: enp1s0 state: up speed: 1000 Mbps duplex: full mac: 00:ce:39:d1:01:01
Bluetooth:
  Device-1: Intel AX201 Bluetooth driver: btusb type: USB
  Report: rfkill ID: hci0 rfk-id: 0 state: down bt-service: enabled,running
    rfk-block: hardware: no software: yes address: see --recommends
Drives:
  Local Storage: total: 230.62 GiB used: 22.29 GiB (9.7%)
  ID-1: /dev/mmcblk0 vendor: Generic model: SCA256 size: 230.62 GiB
    type: Removable
Partition:
  ID-1: / size: 225.65 GiB used: 22.29 GiB (9.9%) fs: ext4 dev: /dev/mmcblk0p2
  ID-2: /boot/efi size: 299.4 MiB used: 288 KiB (0.1%) fs: vfat
    dev: /dev/mmcblk0p1
Swap:
  Alert: No swap data was found.
Sensors:
  System Temperatures: cpu: 99.0 C mobo: N/A
  Fan Speeds (rpm): N/A
Info:
  Memory: total: 8 GiB available: 7.51 GiB used: 2.9 GiB (38.7%)
  Processes: 192 Uptime: 1d 1h 37m Shell: Zsh inxi: 3.3.36

Screenshot_20240817_172934
Screenshot_20240817_1729341920×1179 205 KB

2

Does this computer have fans?

Is the air flow sufficient ?

3

I have a link for the product above. No, it does not have any fans, it has passive cooling, uses its case for it.
The problem is not the actual temps, as it is designed to work like that. The problem is that they are high when (supposedly) does nothing.

4

Have you tried to clean it? Dust is a pretty good insulator. Do you keep that thing in a cabinet? Is there sufficient air flow around it?

5

Is there any specific reason why you are running Plasma on X11 rather than Wayland? Maybe you could try logging in under a Wayland session & see if that fixes the issue.

Also, a quick web search using the terms plasma 6 high cpu x11 found a few possible causes:

  1. A custom theme - try switching to Breeze or Breath if you are not using them

  2. A floating panel - see if disabling the floating panel fixes the issue

  3. The sensors widget (or possibly another widget). Try removing any widgets you have added to your desktop/panel.

  4. A known screenlocking issue (which I think is the most likely cause since the CPU usage goes back to normal after you unlock the session). Again, switching to Wayland might be a solution until it is fixed on X11: 484323 – High CPU load of kwin_x11 when locking or turning off the screen

3 Likes
6

Thank you for that.
I wanted to try this, since the error was X11 related, but I was not sure, I mean, afterall, this is a serious problem/bug.

1 Like
7

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