# cpufreq utils does not recognize CPU after overclocking

## Nitro_146

Hi all,

I had a system with cpufreq utils (cpufreq-set) working since I decided to overclock the CPU.

It's a Core2duo E6300 (1,325V - 1,86Ghz stock) running now at 1,3215 V and 2,45Ghz

The system is stable.

The problem is that cpufreq-set is not working anymore, claiming that it does not recognize the CPU.

 *Quote:*   

> core2 pierre # cpufreq-info 
> 
> cpufrequtils 005: cpufreq-info (C) Dominik Brodowski 2004-2006
> 
> Veuillez rapportez les erreurs et les bogues à cpufreq@vger.kernel.org, s'il vous plait.
> ...

 

Here is cat /proc/cpuinfo output

 *Quote:*   

> processor	: 0
> 
> vendor_id	: GenuineIntel
> 
> cpu family	: 6
> ...

 

Some other infos :

```

core2 pierre # uname -a

Linux core2 2.6.30-gentoo-r4 #1 SMP PREEMPT Thu Aug 20 00:19:58 CEST 2009 x86_64 Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz GenuineIntel GNU/Linux
```

```
core2 pierre # emerge --info

Portage 2.1.6.13 (default/linux/amd64/2008.0/desktop, gcc-4.3.2, glibc-2.9_p20081201-r2, 2.6.30-gentoo-r4 x86_64)

=================================================================

System uname: Linux-2.6.30-gentoo-r4-x86_64-Intel-R-_Core-TM-2_CPU_6300_@_1.86GHz-with-gentoo-1.12.11.1

Timestamp of tree: Sun, 06 Sep 2009 06:15:01 +0000

app-shells/bash:     3.2_p39

dev-java/java-config: 1.3.7-r1, 2.1.8-r1

dev-lang/python:     2.4.4-r13, 2.5.4-r3, 2.6.2-r1

dev-python/pycrypto: 2.0.1-r6

dev-util/cmake:      2.6.4

sys-apps/baselayout: 1.12.11.1

sys-apps/sandbox:    1.6-r2

sys-devel/autoconf:  2.13, 2.63-r1

sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10.2

sys-devel/binutils:  2.18-r3

sys-devel/gcc-config: 1.4.1

sys-devel/libtool:   1.5.26

virtual/os-headers:  2.6.27-r2

ACCEPT_KEYWORDS="amd64"

CBUILD="x86_64-pc-linux-gnu"

CFLAGS="-march=native -O2 -pipe"

CHOST="x86_64-pc-linux-gnu"

CONFIG_PROTECT="/etc /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/share/config /var/lib/hsqldb"

CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/revdep-rebuild /etc/sandbox.d /etc/splash /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c /etc/udev/rules.d"

CXXFLAGS="-march=native -O2 -pipe"

DISTDIR="/usr/portage/distfiles"

FEATURES="distlocks fixpackages parallel-fetch protect-owned sandbox sfperms strict unmerge-orphans userfetch"

GENTOO_MIRRORS="http://ftp.heanet.ie/pub/gentoo/ http://ftp.uni-erlangen.de/pub/mirrors/gentoo http://gentoo.ynet.sk/pub"

LANG="fr_FR.UTF-8"

LC_ALL="fr_FR.UTF-8"

LDFLAGS="-Wl,-O1"

LINGUAS="fr"

MAKEOPTS="-j3"

PKGDIR="/usr/portage/packages"

PORTAGE_CONFIGROOT="/"

PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"

PORTAGE_TMPDIR="/var/tmp"

PORTDIR="/usr/portage"

PORTDIR_OVERLAY="/usr/local/portage"

SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage"

USE="X a52 aac acl acpi alsa amd64 avahi avi berkdb bluetooth branding bzip2 cairo cdr cli cracklib crypt cups dbus divx divx4linux dri dts dvd dvdr eds emboss encode esd evo exif fam firefox flac foomaticdb fortran gdbm gif gimpprint glitz gmedia gnome gpm gstreamer gtk gtk2 hal iconv imagemagick imlib ipv6 isdnlog jbig jpeg jpeg2k lcms ldap libnotify mad matroska mikmod mmx mmxext mp3 mp4 mpeg mudflap multilib ncurses new-login nls nowin nptl nptlonly nsplugin nvidia ogg opengl openmp pam pcre pdf pdflib perl pic png ppds pppd pps print python qt3support quicktime readline realmedia reflection scanner sdl session smp spell spl sse sse2 ssl startup-notification svg sysfs tcl tcpd threads thunar tiff tk truetype trutype unicode usb v4l v4l2 vorbis wmf wmp x264 xinerama xml xmms xorg xpm xulrunner xv xvid zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ELIBC="glibc" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="fr" USERLAND="GNU" VIDEO_CARDS="nvidia"

Unset:  CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, INSTALL_MASK, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

```

----------

## energyman76b

that is normal. cpufreq (and the cpufreq governors in kernel) are depening on bios tables. You overclock, bios tables don't fit anymore/bios doesn't know which ones and doesn't advertise them anymore, kernel sees cpu without tables, no frequency scaling.

And now you know another reason why overclocking is a bad idea.

----------

## Nitro_146

Is it possible to write the desired values in some file ?

Enhanced speedstep is not disabled in the bios, so i would like to use the 6x coefficent when the system is idle and the 7x when I need more horsepower.

Concerning the O/C why do you suggest this is a bad idea ?

I ran this system stock for 3 years. Today I need more power, and rather than buyng a new one, I find this cheaper. (furthermore, the CPU is undervolted and should (?) use less power)

----------

## energyman76b

 *Nitro_146 wrote:*   

> Is it possible to write the desired values in some file ?
> 
> 

 

no. Or maybe. If you hack your bios.

[quote="Nitro_146"

Enhanced speedstep is not disabled in the bios, so i would like to use the 6x coefficent when the system is idle and the 7x when I need more horsepower.

[/quote]

it does not matter if the function is enabled or not. Overclocked the bios does not have the right tables/does not recognize the CPU. OS does not get tables, no speedstep. It is really that simple.

 *Nitro_146 wrote:*   

> 
> 
> Concerning the O/C why do you suggest this is a bad idea ?

 

because overclocking is a great way to create random errors.

----------

## Bircoph

Disable governors at all. If you overclock, you definitely need speed. If you want to save power on overclocked system, use CONFIG_CPU_IDLE=y.

Notes to those objects overclocking.

Overclocking is good if you know what are you doing.

1) I own Athlon XP 2500+ overclocked to 3200+ (technically from 1800 MHz to ~2204 MHz) and it works flawlessly in overclocked mode for 4.5 years, with good cooling of course.

2) I control Celeron D (on Prescott core) and I will never overclock it, because it is known to suffer from thermoelectron diffusion which eventually leads to circuit malfunction.

3) I have EeePC 1000H and I slightly overclocked its core via kernel access to SuperHybrid Engine (cpufv file in sysfs), it works ok together with at least ondemand, performance and powersave governors and I'm happy with it. Moreover, SHE allows to underclock CPU and save power when on battery.   :Smile: 

----------

## Nitro_146

Thank you for those answers.

I have tested my system using memtest,and some intensive softs (big compilations / 2xsuperPI) for a reasonably long time and did not encouter any problem.

My system can work with higher FSB (up to 385Mhz, stock 266, now 350) but some error rarely show up at about 360Mhz, so I reduced it by 10Mhz to be sure...

As I've read, Core2Duo E6300 are good processors for O/c, that's why I gave a try.

I will have a look at that  CONFIG_CPU_IDLE=y.

----------

