Talk:Problem with high pitch noises

2006-02-11T12:13:41Z

Wojtek: /* Harddisk related noise */

==Discussion of "Limit ACPI CPU power states"==

*Stefan Baums: I raised this issue on the linux-kernel mailing list, and from there it was forwarded to the acpi-devel mailing list. See the discussion [http://sourceforge.net/mailarchive/forum.php?thread_id=7593600&forum_id=6102 here] and [http://sourceforge.net/mailarchive/forum.php?thread_id=7599419&forum_id=6102 here]. Results: The <code>idle=halt</code> kernel parameter disables ACPI C-state switching entirely (i.e., locks the processor in C1). It is preferable to pass to the ACPI processor component the option {{bootparm|max_cstate|2}}, which only disables the problematic states C3 and C4. The only way to accomplish this that worked for me was to compile the ACPI processor component permanently into the kernel (<tt>CONFIG_ACPI_PROCESSOR=y</tt>) and then enable it by adding the parameter {{bootparm|processor.max_cstate|2}} to the boot command line (and of course removing {{bootparm|idle|halt}}). Now the computer switches back and forth between C1 and C2, but avoids the noise-inducing C3 and C4, and frequency scaling works regardless. [Update: I now use the default Ubuntu kernel, with <code>processor</code> as a module, and disabled C3 and C4 by modifying {{path|/etc/init.d/acpid}} as explained on the article page.] ({{X41}})
*Simon Eggert: The {{bootparm|processor.max_cstate|3}} option worked for me on my {{T43p}} thanks.
* Adding <code>options processor max_cstate=2</code> in {{path|/etc/modprobe.conf}} (or {{path|/etc/modprobe.conf.local}} on my SuSE 9.3 installation) prevents the CPU permanently from entering into C3 and higher states. ({{X40}}, {{R52}})
* [[User:Thinker|Thinker]]: On one {{T43}}, this worked even with {{bootparm|processor.max_cstate|3}}. That is, C3 was silent and only C4 produced whining (at both HZ=100 and HZ=250).
* [[User:Thinker|Thinker]]: These options affect power consumption when the CPU is idle. Here are the figures on one ThinkPad T43:
** {{bootparm|processor.max_cstate|4}}: 15160mW (default, noisy)
** {{bootparm|processor.max_cstate|3}}: 15770mW (660mW higher, silent)
** {{bootparm|processor.max_cstate|2}}: 16100mW (2940mW higher, silent)

* [[User:Gsmenden|gsmenden]]: On a debian system, no modprobe.conf, can use modutils to add max_cstate line. On my t43p the noise only occcurs when on battery power after suspend / resume cycle. It is definitely is still present when hard disk is spun down. Nevertheless there may be multiple sources of this (quite annoying) sound.

* [[User:Gsmenden|gsmenden]]: Update - if you don't want to use modutils, can manually load it on bootup by adding "processor max_cstate=3" in /etc/modules on a debian system. Noise still present upon resume though on my t43p though :(

* [[User:Nephiel|Nephiel]]: My {{Z60m}} also had the "screeching when on battery" problem with Ubuntu 5.10. Editing {{path|/etc/init.d/acpid}} as described worked. It needed C2: C3 was quieter but still noticeable.

* Michael Kiausch: On my {{x41}} the noise disappears on unloading uhci-hcd module (no matter which c-state), unfortunately this is not an option as this disables usb. ''edit:'' only works if HZ=100

* Just tested M. Kiausch's suggestion on a {{t43}}. The high-pitch noise is gone (HZ=100, cstate=4), but there is a low-pitch noise with about the same "beat". It is much less audible though, and I really had to keep an ear close to the exhaust to hear it. But the noise is still there.

* Michael Kiausch: You're right, same low-pitch-noise on {{x41}}, but it is really hard to hear. Does anyone know in which way the usb-uhci is related to the c-states?

== Harddisk related noise ==

on my T43p the noise definitely comes from the harddisk and can be heard both in Windows and Linux. Only at boot time, before the harddisk spins up, or when I manually spin down the harddisk with

{{cmdroot|hdparm -y /dev/sda}}

the system is silent.

Hi, I don't have an IBM but Dell Latitude D410 laptop. My problem is that not only the high pitch noise is produced but the processor itself comes very busy when speedstep-centrino module is loaded. On karamba monitor (not very reliable but I can feel the difference) I get 50-100% processor occupation. Right now I'm recompiling my 2.6.14 kernel to 100Hz timer freq. (was 250) and we'll see what happens.

If you have any suggestions don't hestite since I practically can't use speedsteping because battery discharges rapidly

Cheers
Wojtek

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Talk:Problem with high pitch noises