Cpu on high speed when idle and low speed when high load

[mahardikahandoko]

I have an acer E5-476G with I5 8250U & 130MX version. I have latest bios & driver installed.

I've done many stress test and i realize my cpu is underclocked from 3.4ghz in idle to max ~2.1ghz under heavy load. When I'm under gaming session, my cpu goes to ~0.8ghz. I've done setting up power plan to performance mode, undervolt, disable speedstep, disable c1e, and none of them works for me.

I have pretty good cooling solution and my temp is never reach 80C so i can assure it's not overheat problem. I've done setting with xtu and throttlestop and did reinstall os in the end to make sure all goes back to default.

This is my spec:
Acer E5-476G
CPU: Intel Core i5 8250 1.8ghz(3.4ghz turbo)
GPU : Intel UHD 620 & NVidia 130MX
RAM : 2x4gb
HDD: WDC 1TB

 

[kookie3010]

open up xtu and turn on power limit throttling monitoring.then run games and check if there is issue with power limit throttle

 

[mahardikahandoko]

open up xtu and turn on power limit throttling monitoring.then run games and check if there is issue with power limit throttle

Thanks for replying!
Yes, sometimes it does power limit throttle but only 3-5 times when in the worst scenarios (many explode effect/many enemies) and only short period (2-5second when the scenario occurs)but the clock was never reach 1ghz. When i run CPU benchmark(R15)/stress test(Prime95) and monitoring the CPU, it doesn't throttle but the clock was only 2.1-2.4ghz.

 

[kookie3010]

is there any bios update for your machine?the issue with power limit throttling is that it happen on some machine when both the cpu and gpu is being utilise together.

 

[mahardikahandoko]

is there any bios update for your machine?the issue with power limit throttling is that it happen on some machine when both the cpu and gpu is being utilise together.

I got latest bios update from the website. I also done installed the latest driver from the website too

 

[kookie3010]

how many wattage is your power adapter

 

[mahardikahandoko]

how many wattage is your power adapter

It said 65W on my ac adapter. I'm not sure if it was power issues but i use stock ac adapter that come with the laptop.

 

[kookie3010]

i see.i seen the same issue on the dell 7567 and 7577 as well.once cpu and gpu is under heavy load the cpu will throttle down.i see that the power limit throttling issue will happen if it reach certain temps.try disabling turbo boost and see if u get the same reading.

 

[mahardikahandoko]

i see.i seen the same issue on the dell 7567 and 7577 as well.once cpu and gpu is under heavy load the cpu will throttle down.i see that the power limit throttling issue will happen if it reach certain temps.try disabling turbo boost and see if u get the same reading.

Gaming issues? done ✔
heavy task (benchmark & stress test)? still same

Ok I turned down the turbo boost and get constant 1.7ghz on gaming and get decent fps but when it comes to rendering a video (adobe family) or some benchmark, that turbo boost was very important. i get ~2.1ghz when turbo boost is turned on but i think it can be 3.4ghz since 8250U can reach max 3.4ghz turbo. are there any ways to get >3ghz? its weird when you get 3.4ghz on idle and but it cant reach more than 3ghz when you really need it(heavy task) :/