# power limit throttling even on idle!!



## islam90 (Aug 6, 2020)

i have acer predator helios 300 with core i7 9750H and it is giving me power limit throttling spikes during idle, in addition to pl2 error during the short time boost and pl1 error during long time boost under stress test.
have anyone encountered this problem with helios 300?


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## unclewebb (Aug 6, 2020)

It is best to run Intel Extreme Tuning Utility or ThrottleStop but do not run both at the same time. Two different programs writing different data to the same CPU register is never a good thing to do.

Your ThrottleStop screenshots show that the long term turbo power limit (PL1) is set to 45W and the short term turbo power limit (PL2) is set to 56W. These are the default settings for the 9750H. During stress testing, if the power limit tries to exceed 56W, the CPU will be forced to throttle so it does not exceed this power limit. This type of throttling will show up as PL2 - CORE combined with EDP OTHER - RING in ThrottleStop.

Long term, if you continue stress testing, this will change to PL1 throttling. Now the CPU is throttled so power consumption does not exceed 45W. The 9750H has a 45W TDP rating so your CPU is running exactly as Intel intended.

Some laptop manufacturers leave these power limits unlocked so you can increase these limits and significantly improve performance. Some laptops are firmly locked down to 45W long term and there is not much you can do about it.

If you want less throttling and more performance and if you are going to use ThrottleStop, check the FIVR - Disable and Lock Turbo Power Limits option. In the TPL window, set the long and short turbo power limits much higher. If you do both of these things and are still getting PL1 throttling at 45W then there is not much you can do about this.

It is also a good idea to go into the Options window and set the PROCHOT Offset value to 3 instead of 8. If this feature is not locked, changing this value will increase the thermal throttling temperature from 92°C to 97°C which is much closer to the Intel recommended value of 100°C. Leaving a couple of degrees of wiggle room is OK. An OEM that starts thermal throttling at 92°C is being way too conservative (cowardly) and has obviously not read the Intel documentation for this processor.









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Edit - For the 9750H, you really should be using ThrottleStop. It allows you to adjust the CPU core and cache offset voltages independently. Leave the cache at -125 mV and slowly bump the core offset up towards -200 mV. Use Cinebench R20 to see if you get an improvement in performance or temperatures by doing this. Most people do. Intel XTU does not allow you to do this.

The throttle indicators within the CPU are hyper sensitive. It is not unusual for these to be briefly triggered even when the CPU is idle. That is what those random spikes in XTU are telling you. Run a ThrottleStop log file. It will show you exactly what your CPU is doing during a stress test. Attach one to your next post and I will explain the data to you.


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## islam90 (Aug 6, 2020)

unclewebb said:


> It is best to run Intel Extreme Tuning Utility or ThrottleStop but do not run both at the same time.
> 
> Your ThrottleStop screenshots show that the long term turbo power limit (PL1) is set to 45W and the short term turbo power limit (PL2) is set to 56W. During stress testing, if the power limit tries to exceed 56W, the CPU will be forced to throttle so it does not exceed this power limit. This type of throttling will show up as PL2 - CORE combined with EDP OTHER - RING in ThrottleStop.
> 
> ...



Thanks for your response, i really apperciate it and i already checked Disable and Lock Turbo Power Limits option so i can increase the long and short turbo power limits *(PL1 70 / PL2 80)* but it only affected the the short turbo power boost till 67W during the short time turbo boost with no error and then the power settled at 45W after the time of the short boost is up although i set PL1 to 70W IN TPL.

but the surprising thing here that when the short time turbo boost is finished and the power settled to 45W
*IT GIVES ME PL2 ERROR NOT PL1* !! (IN CASE OF UNCLAMPED TURBO LONG POWER BOOST)

AND IF I CHECK CLAMP FOR TURBO LONG POWER BOOST
*IT GIVES ME PL1 ERROR* (BUT THE POWER WILL *SETTLE AT 56W*)


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## unclewebb (Aug 6, 2020)

islam90 said:


> and then the power settled at 45W


Intel CPUs have 3 unique sets of turbo power limits. The CPU constantly compares these 3 sets of turbo power limits and it uses the lowest power limit value that it finds.

Some laptops only use 1 or 2 of these power limits. Your computer uses all 3 sets of turbo power limits.

The TPL window in ThrottleStop lets you set the first set of turbo power limits.

The FIVR - Disable and Lock box allows you to turn off the second set of power limits so the CPU will not use these.

The third set of power limits is controlled by the EC. Acer can set these power limits to whatever they like. Your log file shows that your laptop is limited to 45W long term. The third set of power limits are set by Acer to 45W for PL1 and 56W for PL2. These are the Intel recommended default values. Intel says that PL1 should be set equal to the TDP and PL2 should be set 25% higher. 

45W + 25% = 56.25W

The CPU must obey the power limits that Acer has set. That is too bad because some laptops with this same CPU can run long term at 70W or 80W as long as they do not overheat. Some laptops use different fan profiles. If you can switch your computer to a high fan speed profile, it might also increase this third set of turbo power limits.


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