SUMMARY the similarity finder uses about half the CPU clock speed STEPS TO REPRODUCE 1. CPU clock speed measurement 2. High performance mode 3. Use left-side similarity finder OBSERVED RESULT CPU clock speed is about half of the maximum EXPECTED RESULT Max CPU speed SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
Created attachment 137464 [details] Open Hardware Monitor -clock bus speed
Well, digiKam cannot control the hardware clock directly. It would be to test what would happen if we gave the tasks a higher priority. However, there are also a lot of database accesses and these relieve the required CPU core again in the meantime. But do we really want to make the computer inoperable when digiKam is running? Maik
I find your CPU temperature critical, even an Intel CPU should better stay below 80°C. The 80-95°C are possible, but should be avoided. Maik
And Intel, as other CPU have temperature security. 80° is the limit for a safe public core uses. Higher values make CPU unstable and possible internal logic transistors destruction. Military and high critical use (as space module) electronics can be overloaded to 120°C but it's require more tests in build process and this very expensive. So i recommend to check the freeze system for your CPU. Typically the thermal paste, the cpu fan, etc... Gilles Caulier
https://en.wikipedia.org/wiki/Computer_cooling
https://www.buildcomputers.net/cpu-temperature.html
https://en.wikipedia.org/wiki/Operating_temperature
It is strange that during the operation of DK similarity and other resource-intensive processes, the CPU clock speed decreases from the maximum to 54-75%. At the end of the process, it rises to the maximum. Testing was performed with MS Edge open at the same time. This also means other concurrent programs must be able to handle at slowed CPU clock speeds.
But it's clear : as Maik said, the CPU temperature exceed the limit and CPU security turn on to limit clock and de-facto the temperature. To resume : You have a problem with your CPU cooling. Check your system. Gilles Caulier
From the hardware monitor screenshot, we can see all four cores are at 100%, thus operating as expected. As Maik mentioned, it is not digiKam's responsibility to select which CPU clock speed your OS wants to use, we can only request from the OS to provide us with threads for the application to use.
Thanks for the answers. I understand that the search for similarities must work that way. Hannes
As it's an hardware problem i close this issue now. Gilles Caulier