On Thu, Feb 19, 2009 at 2:53 AM, Justin <[email protected]> wrote:

> Martin Herrman schrieb:
> >
> >
> > 2009/2/19 Thanasis <[email protected]
> > <mailto:[email protected]>>
> >
> >     # uname -a
> >     Linux wolfdale 2.6.28-gentoo-r2 #1 SMP PREEMPT Wed Feb 18 13:53:22
> EET
> >     2009 x86_64 Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz GenuineIntel
> >     GNU/Linux
> >
> >     Overclocked the core 2 duo (E8400) from 3 to 4GHz using motherboard
> >     BIOS settings. In mswindblows I can see the overclocked frequency
> >     (when cpu is under load), in linux /proc/cpuinfo never shows beyond
> the
> >     stock 3GHz value.
> >
> >     Q: Is /proc/cpuinfo showing the actual frequency?
> >
> >     # cat cpuinfo
> >     processor       : 0
> >     vendor_id       : GenuineIntel
> >     cpu family      : 6
> >     model           : 23
> >     model name      : Intel(R) Core(TM)2 Duo CPU     E8400  @ 3.00GHz
> >     stepping        : 10
> >     cpu MHz         : 2997.000
> >     cache size      : 6144 KB
> >     physical id     : 0
> >     siblings        : 2
> >     core id         : 0
> >     cpu cores       : 2
> >     apicid          : 0
> >     initial apicid  : 0
> >     fpu             : yes
> >     fpu_exception   : yes
> >     cpuid level     : 13
> >     wp              : yes
> >     flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
> >     pge mca cmov
> >     pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
> lm
> >     constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl
> >     vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 xsave lahf_lm tpr_shadow
> >     vnmi flexpriority
> >     bogomips        : 8099.96
> >     clflush size    : 64
> >     cache_alignment : 64
> >     address sizes   : 36 bits physical, 48 bits virtual
> >     power management:
> >
> >     processor       : 1
> >     vendor_id       : GenuineIntel
> >     cpu family      : 6
> >     model           : 23
> >     model name      : Intel(R) Core(TM)2 Duo CPU     E8400  @ 3.00GHz
> >     stepping        : 10
> >     cpu MHz         : 2997.000
> >     cache size      : 6144 KB
> >     physical id     : 0
> >     siblings        : 2
> >     core id         : 1
> >     cpu cores       : 2
> >     apicid          : 1
> >     initial apicid  : 1
> >     fpu             : yes
> >     fpu_exception   : yes
> >     cpuid level     : 13
> >     wp              : yes
> >     flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
> >     pge mca cmov
> >     pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
> lm
> >     constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl
> >     vmx smx est tm2 ssse3 cx16 xtpr pdcm sse4_1 xsave lahf_lm tpr_shadow
> >     vnmi flexpriority
> >     bogomips        : 8099.74
> >     clflush size    : 64
> >     cache_alignment : 64
> >     address sizes   : 36 bits physical, 48 bits virtual
> >     power management:
> >
> >
> > I have noticed exactly the same while overclocking my Q9300 from it's
> > stock 2.5 GHZ to 3.2 GHZ. Compilation / encode transactions do take much
> > less time, so I assume that the BIOS information is correct and the
> > /proc/ entry is false.
>
> If you downstep your cpu it is shown:
>
> model name      : Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz
> stepping        : 11
> cpu MHz         : 1600.000
>
> But perhaps it just read the step and knows which frequency belongs to
> that.
>
>
I'm pretty sure /proc/cpuinfo is all static information, based on response
from the chip, and not actual run-time frequencies.

If you have the cpufreq module loaded, you can try
/sys/devices/system/cpu/cpu*/cpufreq

... HH

Harry Holt, PMP

"Somebody has to do something, and it's just incredibly pathetic that it has
to be us."
 - Jerry Garcia

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