Why the individual core frequency is different on multi-core Intel processors? Tiger lake

[Hsin]

The EIST define the multi-core CPU have same frequency and voltage, but we measured different result in practice with Tigerlake CPU, the individual core frequency are different either during idle or during workload.

Could you help us to clarify the CPU frequency architecture?

Enhanced Intel SpeedStep® Technology
Enhanced Intel SpeedStep® Technology enables OS to control and select P-state. The
following are the key features of Enhanced Intel SpeedStep® Technology:
• Multiple frequencies and voltage points for optimal performance and power
efficiency. These operating points are known as P-states.
• Frequency selection is software controlled by writing to processor MSRs. The
voltage is optimized based on the selected frequency and the number of active
processors IA cores.
— Once the voltage is established, the PLL locks on to the target frequency.

!!!!!!!!!!!!!!— All active processor IA cores share the same frequency and voltage. !!!!!!!!!!!!!!!!!! In a
multi-core processor, the highest frequency P-state requested among all active
IA cores is selected.

— Software-requested transitions are accepted at any time. If a previous
transition is in progress, the new transition is deferred until the previous
transition is completed.
• The processor controls voltage ramp rates internally to ensure glitch-free
transitions.

[Victor_G_Intel]

Hello Hsin,

Thank you for posting on the Intel® communities.

Mobile processors hit different frequencies based on the manufacturer's power and thermal designs. Configurable TDP-up and down is a processor operating mode where the processor's behavior and performance are modified by raising or lowering the TDP and the processor frequency to fixed points. The use of Configurable TDP-up is typically executed by the system manufacturer to optimize power and performance. The base frequency of all cores would range based on the OEM system design. Using TPD up and TDP down it can be adjusted as noted in ark.intel.com. We can't validate 3rd party test results so our best advice is to check with your system manufacturer to adjust your real-life observations/results with their public specifications per system.

Through Turbo Boost the Max turbo frequency is the maximum single-core frequency at which the processor is capable of operating.

Regards,

Victor G.

Intel Technical Support Technician

[Victor_G_Intel]

Hello Hsin,

Were you able to check the previous post?  

Please let me know if you need further assistance.  

Best regards,

Victor G. 

Intel Technical Support Technician

[Hsin]

Hi Victor, 

I understand the power and thermal design will affect CPU frequency, and my question is invidious cores frequency are different when CPU in turbo condition.  

BR,

Tommy

[Victor_G_Intel]

Hello Hsin,

Thank you for posting on the Intel® communities.

Please let us investigate this further and we will reach out as soon as possible.

Regards,

Victor G.

Intel Technical Support Technician 

[Victor_G_Intel]

Hello Hsin,

Thank you for posting on the Intel® communities.

The processor’s Intel Turbo Boost technology identifies the best performing core by increasing its performance based on the temperature headroom and power requirements. Another fact is that this processor supports Intel Thermal Velocity Boost Frequency which will opportunistically and automatically increases clock frequency above single-core and multi-core Intel Turbo Boost Technology frequencies based on how much the processor is operating below its maximum temperature and whether turbo power budget is available. The frequency gain and duration are dependent on the workload capabilities of the processor and the processor cooling solution.

We can't validate 3rd party test results so our best advice is to check with your system manufacturer to adjust your real-life observations/results with their public specifications per system.

Regards,

Victor G.

Intel Technical Support Technician

[Victor_G_Intel]

Hello Hsin,

Were you able to check the previous post?  

Please let me know if you need further assistance.  

Best regards,

Victor G. 

Intel Technical Support Technician

[Victor_G_Intel]

Hello Hsin,

We have not heard back from you.

If you need any additional information, please submit a new question as this thread will no longer be monitored.

Victor G. 

Intel Technical Support Technician