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[Bug 1389077] Re: [HP ProBook 4530s] Intel Powerclamp is Slowing CPU


My GPU seems fine, well under the high threshold. I can see what the
logic is of throttling the CPU because the GPU is overheating--if the
CPU is throttled then less data is being fed to the GPU so the GPU is
indirectly slowed. But you're right, reducing the CPU by half is
overkill. And that seems to be my problem as well. Without the
powerclamp, my temperature goes slightly over the high threshold, maybe
87 deg with a threshold of 85 degrees, but the idle goes at 50% for
quite some time.

I don't want to remove the powerclamp driver, since I don't want my CPU
to overheat. But 50% CPU reduction to control temperature that is
slightly exceeding the max makes my machine unusable.

Looking at the documentation for the powerclamp technology and the proc
values, it looks like any level under 50% can be selected. I don't think
it is powerclamp itself choosing the value, so there must be some
thermal protection module that is choosing all or nothing. It really
should gradually start injecting until the temperature is acceptable,

** Changed in: linux (Ubuntu)
       Status: Incomplete => Confirmed

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  [HP ProBook 4530s] Intel Powerclamp is Slowing CPU

Status in “linux” package in Ubuntu:

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

  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 
  root@bkat-HP-ProBook-4530s:/sys/class/thermal/cooling_device5# cat cur_state 
  root@bkat-HP-ProBook-4530s:/sys/class/thermal/cooling_device5# cat max_state 

  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
   /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
   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

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