[SOLVED] "CPU throttled at 91% by Windows" possibly overheating?

Apr 4, 2019
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Hello all! I have bought a few days ago new Acer Aspire A515-52-394A with i3-8145U, 8GB ram, 250GB SSD, Windows10 Home and i am very glad with the purchase. However, after performing userbenchmark tests several times, i always get the following warning:"

CPU throttled at 91% by Windows. Ensure maximum processor state is set to 100% via Settings > System > Power & sleep > Additional power settings > Change plan settings > Change advanced power settings > Processor power management > Maximum processor state.

UserBenchmark test results

I have noticed that in the beginning of any benchmark test (OCCT, Prime95) my CPU temperature going up to 93-97 C for several seconds in which its working in full turbo speed around 3900MHz, before normalizing to 82-83c but at the cost of dropping to 2800-2900 MHz. Is this the normal behavior?

Here are screenshots of HWmonitor during and after stress testing

during test screenshot

after test screenshot

Isn't the processor supposed to maintain full turbo boost for as long as it is needed without overheating, not only for 7-8 secs? Also should i be worried about the "CPU throttled at 91% by Windows" warning in userbenchmark test?
I still have about two weeks to return the laptop, so please advice me if you think that it may have a hardware failure or its all normal and expected behavior during the stress testing. Thanks in advance!
 
Last edited:

Chasingfaith

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May 7, 2016
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I have just taken a look at the pictures in your links and it seems like your processor did indeed throttle during the stress test. Keep in mind, however, that stress tests are specifically designed to stress your system and they are therefore not very realistic. For example, when I run "intelburntest" (specifically designed to increase your temps) I observe temperatures that are 20 degrees higher than in any real world scenario.

Even though userbenchmark gave you a warning, your cpu did not throttle during the benchmark and your cpu achieved an average clock speed of 3.7GHz. You got an above average cpu score compared to other computers with the same cpu. This means that your laptop is able to maintain its boost clock in every real world scenario.

The temperatures you observed when intensively using your laptop are perfectly reasonable and therefore I see no reason for you to return your laptop.

Hope this helps :)
 

Chasingfaith

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May 7, 2016
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Your processor (i3 8145u) should be able to maintain a constant speed of 3.7 Ghz over both cores (or 3.9 GHz on a single core) when properly cooled. The behavior you witnessed is called thermal throttling. It means that the processor reduces its speed to prevent damage by overheating. Your specific processor is designed to start throttling once it reaches 100c.

Even though this behaviour is anything but desirable, it is not uncommon for (thin) laptops to throttle when put under continuous load. If this only happens during stress testing I wouldn't worry too much about it. What are your temps under normal load?
 
Apr 4, 2019
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Thank you very much for your answer! just now noticed the links with the screenshots and the results from userbenchmark in my post were not working. i have now corrected them, please check if you can.
About the temps under normal load, i have yet to observe while doing some normal tasks, but they are around 50-70c.
I am wondering if the laptop can`t maintain the boost speed under heavy load, then whats the purpose of it at all, its very disappointing. Do Lenovo laptops do better in this regard, maybe i should return the Acer and take the Lenovo in the link below, what do you think?

https://ardes.bg/product/lenovo-ideapad-330s-15ikb-81f500vfbm-8gb-250ssdnvme-125103
 
Apr 4, 2019
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Just now tested the laptop with two browsers open playing 4k youtube videos, utorrent running and downloading and open office document open, it did not go more than 83c, while mostly stayed in the 50-60c zone and was able to maintain both cores around 3700MHz for long periods without drastic temperature increase. Why this difference between the benchmark and normal use loads? Thanks again for any advice or comment
 

Chasingfaith

Reputable
May 7, 2016
190
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4,765
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I have just taken a look at the pictures in your links and it seems like your processor did indeed throttle during the stress test. Keep in mind, however, that stress tests are specifically designed to stress your system and they are therefore not very realistic. For example, when I run "intelburntest" (specifically designed to increase your temps) I observe temperatures that are 20 degrees higher than in any real world scenario.

Even though userbenchmark gave you a warning, your cpu did not throttle during the benchmark and your cpu achieved an average clock speed of 3.7GHz. You got an above average cpu score compared to other computers with the same cpu. This means that your laptop is able to maintain its boost clock in every real world scenario.

The temperatures you observed when intensively using your laptop are perfectly reasonable and therefore I see no reason for you to return your laptop.

Hope this helps :)
 

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