As an experiment, I removed the powerclamp driver and monitored the temp sensors. The GPU never got close to high. The CPU has two thresholds, high of 86 C and critical of 100 C. With the powerclamp driver, the idle injection always kicked in at 86. Without, the temp stayed at around 99 C, never ever going above 100. So you look like you're right, the CPU must be throttling itself. The PC behaved as it used to, no noticeable slowdown whatsoever.
I will now blacklist the driver and have my PC like it was before. I recommend that the powerclamp driver be disabled by default, as there must be many people who are experiencing unnecessary and dramatic performance reduction, and have no clue what is causing it. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1389077 Title: [HP ProBook 4530s] Intel Powerclamp is Slowing CPU Status in “linux” package in Ubuntu: Confirmed Bug description: I upgraded from KUbuntu 14.04 to 14.10. Immediately, while playing minecraft with my daughter, I noticed the game was running very slowly. Even after closing the game, my web browsing slowed to a crawl. Looking at the processes in top, I noticed there were 4 tasks called kidle_inject running at 50% CPU each. After spending a long time figuring out what caused this, I found out this is caused by the Intel Powerclamp driver. I never did anything to enable this, and haven't observed this slowdown before the upgrade. I found the powerclamp driver in the /sys/class/thermal/cooling_device5 directory: root@bkat-HP-ProBook-4530s:/sys/class/thermal/cooling_device5# cat type intel_powerclamp root@bkat-HP-ProBook-4530s:/sys/class/thermal/cooling_device5# cat cur_state -1 root@bkat-HP-ProBook-4530s:/sys/class/thermal/cooling_device5# cat max_state 50 I tried to echo 0 to cur_state, but it still reported -1 when I catted the value. There seems to be no obvious way to disable this, and this should not have been enabled in the first place. ProblemType: Bug DistroRelease: Ubuntu 14.10 Package: linux-image-3.16.0-24-generic 3.16.0-24.32 ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4 Uname: Linux 3.16.0-24-generic x86_64 ApportVersion: 2.14.7-0ubuntu8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: bkat 2780 F.... pulseaudio CurrentDesktop: KDE Date: Mon Nov 3 23:16:04 2014 HibernationDevice: RESUME=UUID=35e1d874-a3bd-4227-acab-16f3e929d993 InstallationDate: Installed on 2012-04-22 (925 days ago) InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) MachineType: Hewlett-Packard HP ProBook 4530s ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-24-generic root=UUID=743f1686-bfe7-4e32-911d-5371633ccec8 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.16.0-24-generic N/A linux-backports-modules-3.16.0-24-generic N/A linux-firmware 1.138 SourcePackage: linux UpgradeStatus: Upgraded to utopic on 2014-11-03 (0 days ago) dmi.bios.date: 05/13/2011 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68SRR Ver. F.09 dmi.board.name: 167C dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 22.1A dmi.chassis.asset.tag: CNU1284V1X dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68SRRVer.F.09:bd05/13/2011:svnHewlett-Packard:pnHPProBook4530s:pvrA0001D02:rvnHewlett-Packard:rn167C:rvrKBCVersion22.1A:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP ProBook 4530s dmi.product.version: A0001D02 dmi.sys.vendor: Hewlett-Packard To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1389077/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
