CPU/mainboard emmit high sound-noise if the CPU is idle. On 2.6.31-14-generic with quad core intel

[LimCore]

If the CPU is idle (all 4 cores), then there is a high pitch noise coming from the PC box (probably the CPU or some part of mainboard).

This does NOT happen if:
- if I use older kernel from ubuntu 9.04
- If I use kernel 2.6.28-13
- if there is anything running, in example memtester or any program that uses (most of 1 core?) of CPU

otherwise, there is constantly this noise.

It is probably not from fan.

I would guess, too quick frequency scaling causes some strange effect or something?
It is definitely NOT from speakers (nor from PC beeper).

00:00.0 Host bridge: Intel Corporation 4 Series Chipset DRAM Controller (rev 03)
details of harderwer I attached here by apport-bug I hope.

ProblemType: Bug
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: rafal 7371 F.... pulseaudio
                      rafal 8870 F.... kmix
 /dev/snd/controlC1: rafal 7371 F.... pulseaudio
                      rafal 8870 F.... kmix
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xd3220000 irq 22'
   Mixer name : 'Analog Devices AD1882'
   Components : 'HDA:11d41882,80861003,00100300'
   Controls : 41
   Simple ctrls : 24
Card1.Amixer.info:
 Card hw:1 'U0x46d0x804'/'USB Device 0x46d:0x804 at usb-0000:00:1a.7-6, high speed'
   Mixer name : 'USB Mixer'
   Components : 'USB046d:0804'
   Controls : 2
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'Mic',0
   Capabilities: cvolume cvolume-joined cswitch cswitch-joined
   Capture channels: Mono
   Limits: Capture 0 - 6144
   Mono: Capture 3898 [63%] [6.00dB] [on]
Date: Tue Nov 3 03:02:08 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=68f267d8-6ac0-48bd-97e4-9531ffd2358f
IwConfig:
 lo no wireless extensions.

 eth3 no wireless extensions.

 eth2 no wireless extensions.
NonfreeKernelModules: nvidia
Package: linux-image (not installed)
ProcCmdLine: root=UUID=e5818be3-b3f1-4d34-b801-1d8728425e88 ro quiet
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-14-generic 2.6.31-14.16
 linux-firmware 1.24
RfKill:

SourcePackage: linux-meta
Uname: Linux 2.6.31-14-generic x86_64
WpaSupplicantLog:

dmi.bios.date: 10/30/2008
dmi.bios.vendor: Intel Corp.
dmi.bios.version: CBQ4510H.86A.0063.2008.1030.1632
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: DQ45CB
dmi.board.vendor: Intel Corporation
dmi.board.version: AAE30148-206
dmi.chassis.type: 2
dmi.modalias: dmi:bvnIntelCorp.:bvrCBQ4510H.86A.0063.2008.1030.1632:bd10/30/2008:svn:pn:pvr:rvnIntelCorporation:rnDQ45CB:rvrAAE30148-206:cvn:ct2:cvr:

[LimCore (limcore)]

Ok, this is the problem:

cpu whine related to c2,c3 etc cpu states (cstate / states)

http://www.inliniac.net/blog/2008/07/25/fixing-noise-on-ubuntu-hardy-804-aka-setting-max_cstate.html

The work around is to append:
  processor.max_cstate=2
to the /boot/grub/menu.lst line that loads your kernel (remember to backup etc before!) example:

linux /boot/vmlinuz-2.6.31-14-generic root=UUID=b366eab5-0f04-4e8c-9459-0ffd0e6d1b58 ro quiet splash processor.max_cstate=2

read more:
http://ubuntuforums.org/showthread.php?p=8221309

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.