# Intel enhanced speedstep

## rmcarlsson

Dear forum,

does anyone know where I can find information about the available "cpu throttling states" eg. the available frequencies in intel enhanced speedstep for Intel E6xxx, E8xxx and E2xxx. I have tried Intel website but I can not find anything useful.

For my E6300 I can only find two states and the difference is low, like 15%, not so useful.

  Best regrads

  / Mikael

----------

## massimo

How did you find these states? Did get the available states from /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies?

----------

## d2_racing

In fact, theses setting are inside /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies

Also, what governor are you using right now ?

----------

## rmcarlsson

Hi,

my question is "Where can I find specifications that states the supported frequencies for different cpu's, like E8400 0r E2160?". I am not interrested in the Linux interface for controlling the cpu states.

Thanks.

  / Mikael

----------

## coolsnowmen

"Where..." On Intel's site.  Technical Documents

ftp://download.intel.com/design/processor/datashts/

----------

## coolsnowmen

 *rmcarlsson wrote:*   

> For my E6300 I can only find two states and the difference is low, like 15%, not so useful.

 

If I understand correctly, you should have 7 or 8 possible states

----------

## rmcarlsson

Hi,

I just looked in the E6000 specification and I can not find any information about the number of states. In what document and on what page did you dig up "7 or 8".

  Best regards

  Mikael

----------

## coolsnowmen

Its a good think acrobat has a search function, because I don't exactly relish combing through 100s of pages of documentation when RTFM is an acceptable response.

5.2.3 starts on page 96

ftp://download.intel.com/design/processor/datashts/313278.pdf

 *Quote:*   

> On-Demand mode, the duty cycle of the clock modulation is programmable via
> 
> bits 3:1 of the same IA32_CLOCK_MODULATION MSR. In On-Demand mode, the duty
> 
> cycle can be programmed from 12.5% on/ 87.5% off to 87.5% on/ 12.5% off in 12.5%
> ...

 

For what its worth, I searched for "clock"

----------

## rmcarlsson

Strange, as stated before I only see two states. Any ideas?

  / Mikael

----------

## coolsnowmen

I thought you said  *Quote:*   

> I am not interrested in the Linux interface for controlling the cpu states. 

 

I also have 2 states. 2.4Ghz,and 3.0 Ghz on my Core duo (whatever E number maps to 3.0Ghz).  That is a 20% change so I wonder what I am missing.

alas, may I ask exactly what states you have (including the maximum).

I'm using the newer 2.6.24 driver (acpi-cpufreq)  One would have to ask kernel knowledgeable people why. Perhaps it would be worth compiling a non-smp kernel to see if that changes anything (but it doesn't look like it will).  The kernel code does not reveal anything to me.

Edit: well I emailed intel for what its worth. heh

----------

## rmcarlsson

Hi,

I am running Window on that machine now and what can you see in Windows? I bought an AMD64 based machine for my Gentoo box instead of using the E6300 machine, mainly due to the limited EIST. 

I do not recall the exact fequencies, sorry, only that it they were in the region of 1.86 and 1.6x something.

  / Mikael

----------

