# MAJOR Throttling Issue on Core i5 8250U (Lenovo ThinkPad L380 Yoga)



## swaprfast (Aug 12, 2022)

Hi everyone,
So, I've been using my Lenovo ThinkPad L380 Yoga for almost 2.5 years, mostly for light use but recently once I started using it for my semester works (ArcGIS, AutoCAD, and a tad bit of music production), I am noticing one of its biggest flaws. 
The laptop seems to work fine when it's not connected to the charger, not throttling at all and sustaining boost frequencies, not the maximum (3.4GHz), but almost around 2.8 to 3. But once I start charging the laptop and using it, it throttles down abysmally. I tend to keep my laptop connected to the power outlet most of the time, and whenever I do heavy tasks (e.g. using Kontakt as VST on DAW, performing GIS operations etc.), it just throttles, so much so that often it reaches 400MHz, triggering BD Prochot. I tried running the laptop without it but it just shuts down without any warning. This is being a serious issue, even led me to almost fail my semester when it went 400MHz during a GIS operation during my semester finals. 
Any help would be appreciated. I've tinkered a bit with ThrottleStop and am attaching the screenshots and a log of my cinebench run. I am using ThrottleStop 9.5. Thanks in advance!


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## Worthis (Aug 12, 2022)

most of those values seem weird, are u using windows 11 by any chance?


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## swaprfast (Aug 12, 2022)

Worthis said:


> most of those values seem weird, are u using windows 11 by any chance?


Yes, I am using Windows 11. The only tinkering I've done with ThrottleStop are undervolting the core and cache, set the IccMax all the way to the right, and TPL. But nothing seem to explain the sudden 400MHz underclock in heavy tasks and triggering BD Prochot. What values seem weird to you?


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## unclewebb (Aug 12, 2022)

swaprfast said:


> Windows 11


ThrottleStop is not working correctly. You need to disable the Windows 11 virtualization settings so ThrottleStop has full access to the CPU voltage control register.









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After you do that, reboot and delete the ThrottleStop.INI configuration file.

In the FIVR monitoring table, you should not be seeing a column of voltage numbers like 0.3799.

Your laptop does not have adequate cooling to run the CPU at 40W. Either improve your cooling or maybe run your 15W CPU at 15W or 20W. 









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## swaprfast (Aug 13, 2022)

unclewebb said:


> ThrottleStop is not working correctly. You need to disable the Windows 11 virtualization settings so ThrottleStop has full access to the CPU voltage control register.
> 
> 
> 
> ...


I've done everything as per you said
Disabled virtualisation based security (minus the group policy method, my laptop's running Windows 11 Home), deleted the previous throttlestop.ini file, plus I've undervolted my CPU and Cache (attached in the photos below), disabled PL2 (saw it in a guide here i don't know) and set Turbo Power Limits to 20W in TPL. 
The first TS Bench run of 120M showed sustained turbo performance, but as I bumped it up to 960M, it triggered the BD Prochot which instantly hanbraked the CPU frequency down to 400MHz. The same result persists for Cinebench too, albeit a slight increase in multicore points. Disabling BD Prochot causes my system to shutdown.

I was thinking of repasting the laptop a few weeks later. But is the ThinkPad L380 Yoga designed this way? Is there any sort of limit that's aggressively causing BD Prochot to trigger? Or am I doing something wrong? Thanks in advance!

Attaching my logs during a cinebench run, and screenshots below:


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## galacticwarrior448 (Aug 13, 2022)

Your log doesnt seem like you limited it to 20W. Set both short and long PL to 15-20W just to test it and try a 960M bench mark again. If it doesnt throttle, then your issue is probably due to heat. I have seen that this issue is also caused by a faulty power supply at times, it doesnt seem to be that in your case, but it doesnt hurt to try another power adapter.


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## swaprfast (Aug 13, 2022)

galacticwarrior448 said:


> Your log doesnt seem like you limited it to 20W. Set both short and long PL to 15-20W just to test it and try a 960M bench mark again. If it doesnt throttle, then your issue is probably due to heat. I have seen that this issue is also caused by a faulty power supply at times, it doesnt seem to be that in your case, but it doesnt hurt to try another power adapter.


I've attached a screenshot of my TPL window above, and I set both the Long Power PL1 and Short Power PL2 (enabled it later) to 20 and the time limit to 28. But as you said, it doesn't seem like it's limited to 20W from the log. Are there other settings to be changed that I'm missing to limit the CPU to 15-20W?


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## galacticwarrior448 (Aug 13, 2022)

swaprfast said:


> I've attached a screenshot of my TPL window above, and I set both the Long Power PL1 and Short Power PL2 (enabled it later) to 20 and the time limit to 28. But as you said, it doesn't seem like it's limited to 20W from the log. Are there other settings to be changed that I'm missing to limit the CPU to 15-20W?


check the short power tickmark


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## unclewebb (Aug 13, 2022)

Check Short Power PL2 and check the Clamp option for both PL1 and PL2.



swaprfast said:


> I was thinking of repasting the laptop


Do not just think about it, just do it. Sooner the better. Access to the CPU was easy in my daughter's similar Lenovo laptop.

Once you get the power limits properly setup with Clamp enabled, you should be able to clear the BD PROCHOT box. again. Some heatsink might be full of dust so it is not able to do its job.

Edit - Your CPU running constantly at 100°C when BD PROCHOT is disabled is likely the true cause of your system shutting down. Set a PROCHOT Offset value of 5 or 10 in the Options window so your CPU never gets up to 100°C.. It will start to thermal throttle at 95°C or 90°C instead to help avoid a shutdown.

Here is the sorry excuse for a heatsink that Lenovo uses in their laptops.

A three point mounting system and a microscopic layer of gold paint. A proper copper block would not have been that expensive. Intel's 8th Gen U series mobile CPUs can easily run at up to 40W when properly cooled. This sad heatsink is an engineering fail. Not sure why all companies shoot for the bare minimum.


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## swaprfast (Aug 13, 2022)

unclewebb said:


> Check Short Power PL2 and check the Clamp option for both PL1 and PL2.
> 
> 
> Do not just think about it, just do it. Sooner the better. Access to the CPU was easy in my daughter's similar Lenovo laptop.
> ...


I've set both *PL1 and PL2 to 15W clamped* now, and reran the benchmarks. The laptop's fairly stable and doesn't go into the 400MHz state triggering BD Prochot that much, though it still did a bit while I was running Cinebench for the first time after adjusting TPL settings. Attaching the log of my Cinebench run again. It's power limit thottling now and has an almost constant frequency of *2.5GHz *(instead of the 3.4GHz turbo mentioned and set). I'm assuming that is by design or the max second turbo frequency the processor has to offer? Is thermal repaste gonna help here?
Thank you for helping me out so far Unclewebb! It's been such a bummer for the last few months seeing my system throttle down to the megahertz. It's way better at 2.5GHz now, albeit not what the full potential of what the chip has to offer.


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## unclewebb (Aug 13, 2022)

Your CPU cannot run at its full rated speed when Clamped to 15W. If you want full speed, you need to improve the cooling so you can increase the power limits.

Did you change PROCHOT Offset yet? This is a good way to control the maximum CPU temperature which should allow you to clear the BD PROCHOT box.

You might be OK at 20W with Clamp checked and PROCHOT Offset set to 5 as long as it is not Locked. If you see a Lock icon near this setting, leave it alone. You cannot change the offset value if it is locked by the BIOS.


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## swaprfast (Aug 15, 2022)

unclewebb said:


> Your CPU cannot run at its full rated speed when Clamped to 15W. If you want full speed, you need to improve the cooling so you can increase the power limits.
> 
> Did you change PROCHOT Offset yet? This is a good way to control the maximum CPU temperature which should allow you to clear the BD PROCHOT box.
> 
> You might be OK at 20W with Clamp checked and PROCHOT Offset set to 5 as long as it is not Locked. If you see a Lock icon near this setting, leave it alone. You cannot change the offset value if it is locked by the BIOS.


I've done some testing in the last two days and 20W with clamp checked and PROCHOT offset set to 5 is probably all my system can do currently without a repaste. Attaching the logs of my cinebench run here, it's thermal throttling mostly. Thank you unclewebb! By the way, have you got any other suggestions for improving thermals that might help alongside a repaste on these laptops? I've seen your C930 able to sustain around 40W and 3.7GHz on all cores and that amazes me!


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## galacticwarrior448 (Aug 15, 2022)

swaprfast said:


> I've done some testing in the last two days and 20W with clamp checked and PROCHOT offset set to 5 is probably all my system can do currently without a repaste. Attaching the logs of my cinebench run here, it's thermal throttling mostly. Thank you unclewebb! By the way, have you got any other suggestions for improving thermals that might help alongside a repaste on these laptops? I've seen your C930 able to sustain around 40W and 3.7GHz on all cores and that amazes me!


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