Upstream kernel 4.17.0-rc4 didn't change performance. Recall that I installed Kubuntu. Since then I have installed ubuntu- gnome-desktop, in case that provided some missing configuration file.
With either kernel, I get this behavior: - I boot the laptop. - Instead of logging into a desktop environment, I use virtual terminals. - Usually /proc/cpuinfo shows all 8 CPUs running at 900 MHz, give or take a few Hz. Sometimes it shows 400 MHz, but it soon rises to 900 MHz. - I run the c-ray benchmark. CPU frequency rises to 2400 MHz, and stays there for tens of seconds, then drops to 400 MHz. - The laptop does not become warm, and the fans do not spin up. - I kill c-ray. A few minutes later, CPU frequency rises from 400 MHz back up to 900 MHz. - kern.log contains "intel_powerclamp: Start idle injection to reduce power" within seconds of the times when the frequency drops to 400 MHz, and "intel_powerclamp: Stop forced idle injection" when it rises to 900 MHz. Is the cooling system failing to activate the fans, or overreacting to CPU temperatures in some way? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769236 Title: CPU frequency stuck at minimum value To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1769236/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs