# Overclock works in Windows, but not in Gentoo

## obsrv

Hello,

I clocked my Intel Core 2 Duo E6300 CPU from 1,8GHz to 2,4GHz, in Windows it shows normally CPU frequency 2,4GHz, but in Gentoo it does not listen to BIOS, but uses CPU native frequency (1,8GHz), what might be the problem? What information I need to provide for you gurus, so you can help me?  :Smile: 

 :Smile: 

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## ssteinberg

If you set the fsb and multiplier in BIOS then it works, frequency display is incorrect.

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## obsrv

Yes I set FSB freq in BIOS, where I can see my current 2,4GHz to be sure it is seen in Gentoo? Maybe lm_sensors can help? Now compilling modules for it...

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## rh1

Not sure about a core 2 but i know it displays incorrect frequency on my i7. I use a program called i7z to see the correct frequency. Not sure if there is something similar for core 2.

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## NeddySeagoon

When your overclock fails in Gentoo, you get to keep all the pieces.

Gentoo works your CPU much harder than Windiows

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## ssteinberg

 *obsrv wrote:*   

> Yes I set FSB freq in BIOS, where I can see my current 2,4GHz to be sure it is seen in Gentoo? Maybe lm_sensors can help? Now compilling modules for it...

 

If you set the FSB in the BIOS then it is set. lm_sensors has nothing to do with it.

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## krinn

isn't it just a poor reading ?

from cat /proc/cpuinfo you will see actual mhz but intel now keep naming its cpu with its native speed.

```
model name   : Intel(R) Core(TM) i7 CPU         950  @ 3.07GHz <-- never change

stepping   : 5

cpu MHz      : 3074.011 <--- your overclock should be seen here

```

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## rh1

 *Quote:*   

> isn't it just a poor reading ? 

 

You might be right for overclocking. I should re-phrase and say on my laptop it never reports the  Turbo Boost correctly. I thought that was almost the same thing but will confess a lack of knowledge in the area.

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## ssteinberg

 *krinn wrote:*   

> isn't it just a poor reading ?
> 
> from cat /proc/cpuinfo you will see actual mhz but intel now keep naming its cpu with its native speed.
> 
> ```
> ...

 

No, it seems clock is calculated by multiplier X base fsb, regardless of the actual fsb set in BIOS. So if I lowered the multiplier but increased the FSB the kernel reports lower frequency while it is actually much higher. 

On my Core 2 I had the same problem, didn't really bother me as a simple bench showed that the system is indeed running and benefiting from a higher clock speed and much wider FSB.

For the OP again: Your overclock is working, just not showing.

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## Ant P.

Depends on the CPU. My AMD chip always shows the correct frequency, the Intel Atom in my netbook thinks it's always at 1.6 even when it's over/underclocked.

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## Bircoph

 *Ant_P wrote:*   

> Intel Atom in my netbook thinks it's always at 1.6 even when it's over/underclocked.

 

Same here. You can use x86info to measure real frequency:

```

$ x86info -mhz

```

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## drescherjm

 *ssteinberg wrote:*   

>  *krinn wrote:*   isn't it just a poor reading ?
> 
> from cat /proc/cpuinfo you will see actual mhz but intel now keep naming its cpu with its native speed.
> 
> ```
> ...

 

I have observed this behavior on core2 and i-series processors. You still do get the overclock just the frequency is reported as you describe above. The interesting thing is if I run a windows vm on this host windows itself shows the correct frequency of the overclock. Also if you disable frequency scaling then linux will display the correct frequency. At one point I thought that I was not getting the overclock to the point that I modified the acpi_cpufreq driver only to find out that the BIOS overclock was truly working and i was wasting my time forcing the /proc/cpuinfo to display the correct frequency.

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## drescherjm

 *Bircoph wrote:*   

>  *Ant_P wrote:*   Intel Atom in my netbook thinks it's always at 1.6 even when it's over/underclocked. 
> 
> Same here. You can use x86info to measure real frequency:
> 
> ```
> ...

 

Now that actually worked.

I have the frequency set at 155 MHz and the multiplier is 20 without turbo boost.

x86info v1.25.  Dave Jones 2001-2009

Feedback to <davej@redhat.com>.

```
Found 8 CPUs

--------------------------------------------------------------------------

CPU #1

EFamily: 0 EModel: 1 Family: 6 Model: 26 Stepping: 4

CPU Model: Core i7 (Nehalem)

Processor name string: Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz

Type: 0 (Original OEM)  Brand: 0 (Unsupported)

Number of cores per physical package=8

Number of logical processors per socket=16

Number of logical processors per core=2

APIC ID: 0x0    Package: 0  Core: 0   SMT ID 0

3.10GHz processor (estimate).
```

While /proc/cpuinfo shows 2.793GHz. 133 X (20 +1) 

the +1 is for Turbo Boost.

```
processor       : 7

vendor_id       : GenuineIntel

cpu family      : 6

model           : 26

model name      : Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz

stepping        : 4

cpu MHz         : 2793.000

cache size      : 8192 KB

physical id     : 0

siblings        : 8

core id         : 0

cpu cores       : 4

apicid          : 1

initial apicid  : 1

fpu             : yes

fpu_exception   : yes

cpuid level     : 11

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 rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida dts tpr_shadow vnmi flexpriority ept vpid

bogomips        : 6182.44

clflush size    : 64

cache_alignment : 64

address sizes   : 36 bits physical, 48 bits virtual

power management:

```

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