cancel
Showing results for 
Search instead for 
Did you mean: 
RTitus
Level 1
4 2 0 0
Message 1 of 4
276
Flag Post
HP Recommended

Spectre x360 i7-8705G Turbo Boost not functioning correctly

Spectre x360 15-ch0xx
Microsoft Windows 10 (64-bit)

It seems that Turbo Boost on the 8705G is not performing as it does on other Intel laptops. 

 

Intel Turbo Boost is generally designed to have multiple power levels e.g. PL1, PL2 etc. For the first few seconds of load the CPU is in PL2 where it should be able to draw upwards of 50W as evidenced by my Surface Pro which is functioning correctly.

However, the Spectre laptop seems to have a 45W hard limit and never exceeds it. 

This results in the odd phenomenon where my 15W passively cooled tablet outperforms my thick laptop in bursty workloads were the CPU is loaded for a few seconds at a time.

 

I have reinstalled Windows 10 on my Spectre and the 45W CPU limit seems to be fixed, can someone test this to see if it's an issue with my unit?

 

3 REPLIES 3
HP Support Agent
HP Support Agent
19,555 19,544 1,293 1,958
Message 2 of 4
242
Flag Post
HP Recommended

Spectre x360 i7-8705G Turbo Boost not functioning correctly

@RTitus,

 

Welcome to the HP Support Community!

 

I assure you I will try my best to get this sorted.

 

Turbo Boosts operates under the operating system's control and is engaged automatically when the OS requests the highest performance state ("P0"). The amount of time the processors remains in Turbo Boosts depends on the workload and OS requests.

 

There is no setting or options to change or increase the power limit. The number of active cores, which Intel defines as cores in "C0" or "C1" states ("C3" and "C6" states are 'inactive'), dictates the upper limit. Generally, the more active cores, the lower the highest clock frequency Turbo Boost can allow as it's easier to exceed various electrical limits. For example, a dual-core 2 GHz MPU may allow a boost of 266.66 MHz (to 2266.66 MHz) when a single core is active but only 133.33 MHz (to 2133.33 MHz) when two cores are active. (Note that if the thermal and electrical limits have been exceeded, Turbo Boost will be limited even further).

 

Hope that answers your question and you have a great day!

 

If you wish to show appreciation for my efforts, mark my post as Accept as Solution. Your feedback counts!

 

Cheers!

The_Fossette
I am an HP Employee

RTitus
Level 1
4 2 0 0
Message 3 of 4
235
Flag Post
HP Recommended

Spectre x360 i7-8705G Turbo Boost not functioning correctly

Thank you for the response.

 

It seems that you sufficiently understand P-states to help me troubleshoot my issue. It seems that my i7-8705G lacks a PL2. PL1 is 45W, and that is okay. Is it missing PL2 by design?

 

Secondly, under artificial load on AC, the CPU multiplier will at times get locked to x8 (~800MHz), this not a thermal issue as it has occured when the CPU was under 80C and worse is that it stays at 800MHz until a restart. The load is being generated by the Intel Processor Diagnostic Tool. What causes the processor to enter this 800MHz state?

0 Kudos
HP Support Agent
HP Support Agent
19,555 19,544 1,293 1,958
Message 4 of 4
203
Flag Post
HP Recommended

Spectre x360 i7-8705G Turbo Boost not functioning correctly

@RTitus,

 

It is great to have you back and your patience is greatly appreciated.

 

I recommend you contact tech support so that they can take remote of your computer and check.

 

Here is how you can get in touch with the tech support.

1)Click on this link - www.hp.com/contacthp/

2)Select the product type.

3)Enter the serial number of your device or select let HP detect your product option.

4)Select the country from the drop-down.

5)You should see the HP phone support number or Chat option listed.

 

Good day! Take care 🙂

 

Cheers!

 

The_Fossette
I am an HP Employee

0 Kudos
† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the Terms of Use and Rules of Participation