Re: [gentoo-amd64] Is /proc/cpuinfo showing the actual frequency ?

[Martin Herrman]

2009/2/19 Thanasis <thanasis@××××××××××.org>

> # 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.