Severe freezing when saving config or refreshing sensors

[Superino45]

Hi guys,

I've been having a serious problem for several months now. Every time I update a sensor, save settings, or update fan speeds, the app freezes when it reaches the saving point.

Specifically, when it finishes, the "Done" message stays stuck on the screen and the app locks up.

Sometimes after several minutes it unfreezes and I can save my configuration, but it's very frustrating. I have tried everything and almost every version.

Any advice? Thanks.

[Rem0o]

What's your specs?

[Superino45]

Here are my specs: Motherboard: ASUS ROG Maximus Z790 Apex CPU: Intel Core i9-13900K Cooling: Full custom water loop Pumps: 2x D5 pumps Fans: Noctua fans and Phanteks T30 Controllers: Several Aquacomputer components (High Flow NEXT, Octo/Quadro, etc.) Note: I want to clarify that the freezing issue with the "Done" message stuck was happening even before I installed the Aquacomputer components, so they are not the cause.

[Rem0o]

Can you show what sensor sources you got enabled? If you got many, try and isolate. Remove them one by one and see if it still freezes.

[Superino45]

tried exactly what you suggested. I disabled/removed sensor sources one by one to isolate the issue.

Unfortunately, the behavior is the same:

Even with very few sensors enabled, the app still freezes upon saving.

It either locks up completely or takes several minutes (literally 2-5 minutes) hanging on the "Done" message before it finally saves and unfreezes.

It doesn't seem to matter which specific sensor source is active; the "save/apply" process itself seems broken or getting stuck on something else.

[Rem0o]

Wait that's the auto-calibration dialog? Because that's not what I understood from your messages. Be specific as to which dialog "freezes". Is it only the one you showed in the screenshot or there are others?

[Superino45]

Sorry for the late reply.

At this point, Fan Control freezes in almost every situation, even when I just try to save or rename a configuration. Sometimes, after a few minutes in this frozen state, it suddenly unfreezes and starts working again.

This started after I added PawnIO. Before installing PawnIO, Fan Control was working fine on my system. Now, even if I go back to v237, the app still freezes the same way. I also tried a full Windows reinstall and a fresh Fan Control install, but the behavior did not change.

I already tried using fewer sensors and disabling sources, but it still becomes unstable and hangs when saving. The only hardware change on my side in this period was adding some Aquacomputer controllers, but the freezes were already happening before installing those, so they are likely not the cause.

[hmzuleta]

@Superino45 I have the same situation. I don't think it's hardware related, but rather after the PawnIO driver change happened. To be clear, the freeze is a literal main UI thread complete freeze that takes about 5-10 seconds. This happens on any of the views of the application, regardless if you're in the Home, Theme, Tray Icon, Settings, or About tab. It blocks scrolling, UI updates, everything.

My specs:

I'm also running HWinfo64 in the background. I tried:

1. Disabling all sources in the settings. This stopped the UI freezing bug, so I think you're on the right track.
2. Enabling Motherboard source only. The UI freezing bug didn't happen, even if I added a custom sensor for the max temp of all Motherboard hardware sensors. I paired the first fan I detected to this custom sensor for the next tests.
3. Enabling Motherboard + Storage, with the default 60s update + NVAPI, NVIDIA 0%, and AMD ALX. Same results as step 2: no UI freezing. I also added the Nvidia sensors to the max temp custom sensor.
4. Step 3 + Memory. Same results, no freezing.
5. Step 4 + Controller. Same results, no freezing.
6. Step 5 + CPU. Freezing started, even if I didn't add any HW sensors to the custom sensor.
7. Step 5 without Nvidia GPU sources + LHM GPU (i.e. no CPU). No freezing.
8. New configuration with every single source off, except for CPU. Freezing started again. This configuration had nothing! Not even a graph, not even added fans or graphs, only the CPU check turned on.
9. Old configurations, with CPU LHM sensors turned off. Worked like a charm.
10. EDIT: tried the old configurations, with CPU LHM sensors turned on, but I stopped HWinfo64 to check whether the combination was causing this. Nope, still froze.

My conclusion is that there must be some issue with the sensor refresh for LHM CPU sources. It's blocking the UI thread A LOT, so my guess is that there's some heavy or iterative process that is hitting the app hard. I don't see any relevant issues reported on their repo, so I bet there's something else involved (maybe PawnIO? :eyes:). It is especially egregious if you have multiple custom sensors that rely on CPU sources from LHM. @Rem0o does the above ring any bells? I don't see any recent enough code updates in LHM Lib CPU sources (3+ months ago), and it's weird that happens on both AMD and Intel, on Gigabyte and Asus boards alike.

For now, I'll create a copy of my existing user configuration without the CPU's own sensors, and use the motherboard's CPU temp sensor instead.

[Rem0o]

Good investigation to narrow it down to the CPU source.

it's weird that happens on both AMD and Intel,

Any report on Intel? Such issue I would expect to be specific to a module, here the AMD one in your case.

[hmzuleta]

Good investigation to narrow it down to the CPU source.

it's weird that happens on both AMD and Intel,

Any report on Intel? Such issue I would expect to be specific to a module, here the AMD one in your case.

The build from the original bug report by @Superino45 is using an Intel Core i9-13900K right?

[Rem0o]

@hmzuleta if you run LHM from a nightly build, do you get the same freezing in that app?

[hmzuleta]

@Rem0o no, it looks good to me, no stutters

I downloaded it using this link: https://github.com/LibreHardwareMonitor/LibreHardwareMonitor/actions/runs/20097968796/job/57661100856#step:10:25

[Rem0o]

Any particular action to trigger the freezing? I need to be able to reproduce the issue to debug it.

[hmzuleta]

I tried reproducing it myself after I "fixed" it, and wasn't able to. I noticed that the profile that was working for me still had the calibration warnings, because I hadn't done it... and after clicking on the calibration button and letting it auto calibrate it, then it started happening again. So I think it's related to auto fan calibration and LHM CPU readings. This is the configuration I have which is affected by the UI stutters after calibration: cpu-stutters.json

Edit: I might be completely wrong, but if I tried replacing the calibration to "Calibration": [], the stutters continued, and if I changed it to "Calibration": null, the issue went away.

The above is all wrong, the issue came back after some time regardless of the calibration whenever the LHM CPU source was selected. 😢 This configuration is not affected: userConfig.json