topic Re: Programming MSR to read Turbo in Mobile and Desktop Processors

Programming MSR to read Turbo

CCOUR4 — Sat, 04 Jan 2014 15:43:01 GMT

Processor [Intel(R) Core(TM) i7 CPU 920 @ 2.67GHz]

Core# @ Freq. MHz Temp.°C Usage

000 1920 [12 x 160] [ 49 ]:#

001 1920 [12 x 160] [ 48 ]:#

002 1920 [12 x 160] [ 48 ]:#

003 1920 [12 x 160] [ 47 ]:#

004 3200 [20 x 160] [ 49 ]:#

005 3200 [20 x 160] [ 48 ]:#

006 3200 [20 x 160] [ 48 ]:#

007 3200 [20 x 160] [ 47 ]:#

J'ai programmé pour Linux http://code.cyring.fr/FTS/Source/C/zfreq.c zfreq.c qui affiche les ratios du Core i7 Nehalem.

(à compiler avec un simple 'gcc zfreq.c -o zfreq' puis exécuter en tant que root)

Cependant à aucun moment les registres MSR ne retournent des ratios situés dans les valeurs Turbo.

J'ai essayé plusieurs combinaisons BIOS : avec ou sans hyperthreading, 2 à 4 coeurs actifs, coefficient automatique ou fixe

Mauvaise lecture des MSR ?

Merci pour vos tuyaux

Re: Programming MSR to read Turbo

Kevin_M_Intel — Mon, 06 Jan 2014 20:02:21 GMT

Hello gt86,

I am afraid to say that the support is provided in English only. Can you port your query again in English?

Re: Programming MSR to read Turbo

CCOUR4 — Thu, 09 Jan 2014 20:26:53 GMT

Hello Kevin,

My source code http://code.cyring.fr/FTS/Source/C/zfreq.c http://code.cyring.fr/FTS/Source/C/zfreq.c displays the frequencies of the i7 cores.

I'm using the MSR registers to read the core ratios multiplied by the current external clock from the SMBIOS.

However whatever the system load is, the MSR IA32_PERF_STATUS never returns the values found in the turbo zone given by MSR_TURBO_RATIO_LIMIT.

To be short IA32_PERF_STATUS never goes above MSR_PLATFORM_INFO.MaxNonTurboRatio

Please help me to program correctly those MSR

Thank You

CyrIng

Fyi, new forum http://software.intel.com/en-us/forums/topic/499128 thread

Re: Programming MSR to read Turbo

Kevin_M_Intel — Fri, 10 Jan 2014 16:45:11 GMT

Hello gt86,

I am sorry to hear you are having problems but let me guide you.

The information of internal configuration and manipulation of the MSR of the processor is not available and the support on that is limited. If you would like to get this information is necessary for you to contact an Intel® Field Application engineer.