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Max. performance, ThrottleStop still throttles, but in a weird way

adrianpip2000

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I'm having an issue with throttling on my Lenovo 720s 14IKB, which has an Intel i5-8250U processor. I installed ThrottleStop 8.70.6 a while ago, but I'm now trying to make a profile for maximum performance. These are the settings that I'm currently at, including a Cinebench score (no other software running):

  • TPL
    • Turbo Boost PL (Long/Short): 28/30
    • PP0 Current Limit: 100
  • FIVR
    • "Disable and Lock Turbo Power Limits" checked
    • Turbo Ratio Limits: all 34 (standard and maximum, it seems)
    • Undervolting: -80.1 (CPU Core + CPU Cache)
  • Max. temp. with Cinebench: 85C
  • Cinebench R23 Multi Core score: 3215

When I run TS Bench or Cinebench, the PKG Power rises to 30W for a short while (I guess 28 sec), but afterwards it throttles down to around 18W, instead of the 28 I have set it to. I will note that the original Turbo Boost Power Limit setting was 18 (although I don't remember if I changed it to that a long time ago or if I just never touched that setting). Furthermore, PROCHOT (in the main window) stays at 100C for the whole time, and PL1 goes red (in Limit Reasons) when it throttles, so it seems to me that this certainly isn't thermal throttling. I will also note that before I had installed the RwDrv.sys, changing Turbo Boost Power Limit had no effect.

Can anyone (looking especially at unclewebb, since they seem to be one of the pros) help me optimize my settings and/or help me figure out what is wrong? Is it just some limit that Lenovo or Intel has imposed on the computer? Still, it seems weird that I'm able to affect the Turbo Boost Power Limit Short but not Long.

I've attached screenshots of my settings, as well as one of the initial Turbo Boost when running TS Bench, and one where the throttling has come into effect.
ts1.pngts2.pngts3.pngts4.pngts5.pngts6.png

PS: As a side note, is there any good reason to update ThrottleStop to the newest version? If so, can I copy the .ini file from this version, or do I have to manually change all of the settings?

EDIT: I realize that the Cinebench score might be the best I can hope for, but I don't see why I can't run at higher Turbo Boost Power Limits (other than maybe hardware imposed limitations). So frustrating when it at the very least seems to be able to do it for a short while.

EDIT 2: After a bunch of fiddling around, I saw something called Intel Dynamic Platform and Thermal Framework (DPTF) in the advanced power settings of Windows. I've attached a screenshot of it.
win-poweroptions.png
This seems to be limiting TDP at around 18W (actually 18.8W). Annoying. Searched around for a bit, and ended up trying to just disable DPTF in the BIOS, which was possible. However, this led to even more severe throttling (TS Bench), actually staying around 7.5W (see screenshot).
ts7_wo-dptf.png
So I tried following a guide (https://bradshacks.com/disable-dptf/) I found for removing any DPTF software (after having enabled DPTF in the BIOS again). This made no difference (same problem as originally, i.e. short boost, then throttle @ 18W). Then I disabled DPTF in the BIOS (so that I had both followed the guide and disabled DPTF in the BIOS). Throttling at 7.5W came back. I also tried unchecking the "Disable and Lock Turbo Power Limits" when I had DPTF disabled in BIOS, which made no difference. So I reverted the things I did in the guide and enabled DPTF in BIOS again, and now I'm back to scratch...
 
Last edited:

unclewebb

ThrottleStop & RealTemp Author
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Start by upgrading to the latest version of ThrottleStop.

I will also note that before I had installed the RwDrv.sys, changing Turbo Boost Power Limit had no effect.
With the old version of TS, the Disable and Lock Turbo Power Limits feature would not do anything unless the RwDrv.sys driver was installed. The new version of ThrottleStop no longer uses this driver so you can delete it and you can also delete all of the WinRing0 drivers too. The latest TS version is self contained so the driver is built into it. There is nothing else to download or install.

Intel gave the 8250U CPU a 15W TDP limit.

Some manufacturers limit these CPUs so at best, they barely exceed 15W. Some manufacturers come up with some really excessive throttling schemes so they barely exceed 7.5W. This CPU has a 10W configurable TDP-down mode so even being able to run at the default 15W TDP limit is not guaranteed. I would be hesitant to buy a device with this CPU because you just don't know what you are going to end up with. A laptop with an 8th Gen CPU could be a beast or it could be a slug.

I got lucky. The Lenovo C930 I bought had fully unlocked power limits so I was able to achieve some impressive results with it. The only throttling is thermal throttling.


With the new version of ThrottleStop, try checking the FIVR - Disable and Lock Turbo Power Limits option. Also check the Lock option near the top of the TPL window in the Turbo Boost Power Limits section. With both of these items checked, see if your laptop still power limits throttles, either PL1 or PL2 in Limit Reasons. If it does, there is likely nothing you can do about this. There are 3 unique sets of turbo power limits. ThrottleStop does not have access to control the third set. If a manufacturer uses the EC to enforce this third set of turbo power limits, there is nothing that ThrottleStop or Intel XTU can do about that.

Your screenshot shows TDP Level unchecked and set to 2. Just like the power limits, a laptop can also force what TDP Level a CPU operates in. Try checking this option and set it to 0. It might not do anything. With this being duplicated, it is possible that setting this in ThrottleStop will also be overridden by the EC.

Your screenshots show that you do not have Speed Shift Technology enabled yet. You have Speed Shift EPP checked on the main screen but this will not do anything. First you have to go into the TPL window and enable Speed Shift. After you do this, you should see SST in green on the main screen which confirms that Speed Shift Technology is enabled. This probably will not make any difference to your power limit problem but it might help with overall responsiveness.

I was going to suggest to keep your eyes open for a cheap C930 on eBay but there is nothing cheap about their price. Maybe too many people know what the 930 is capable of after some power limit tweaking.
 

adrianpip2000

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Joined
Jan 20, 2021
Messages
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Start by upgrading to the latest version of ThrottleStop.


With the old version of TS, the Disable and Lock Turbo Power Limits feature would not do anything unless the RwDrv.sys driver was installed. The new version of ThrottleStop no longer uses this driver so you can delete it and you can also delete all of the WinRing0 drivers too. The latest TS version is self contained so the driver is built into it. There is nothing else to download or install.

Intel gave the 8250U CPU a 15W TDP limit.

Some manufacturers limit these CPUs so at best, they barely exceed 15W. Some manufacturers come up with some really excessive throttling schemes so they barely exceed 7.5W. This CPU has a 10W configurable TDP-down mode so even being able to run at the default 15W TDP limit is not guaranteed. I would be hesitant to buy a device with this CPU because you just don't know what you are going to end up with. A laptop with an 8th Gen CPU could be a beast or it could be a slug.

I got lucky. The Lenovo C930 I bought had fully unlocked power limits so I was able to achieve some impressive results with it. The only throttling is thermal throttling.


With the new version of ThrottleStop, try checking the FIVR - Disable and Lock Turbo Power Limits option. Also check the Lock option near the top of the TPL window in the Turbo Boost Power Limits section. With both of these items checked, see if your laptop still power limits throttles, either PL1 or PL2 in Limit Reasons. If it does, there is likely nothing you can do about this. There are 3 unique sets of turbo power limits. ThrottleStop does not have access to control the third set. If a manufacturer uses the EC to enforce this third set of turbo power limits, there is nothing that ThrottleStop or Intel XTU can do about that.

Your screenshot shows TDP Level unchecked and set to 2. Just like the power limits, a laptop can also force what TDP Level a CPU operates in. Try checking this option and set it to 0. It might not do anything. With this being duplicated, it is possible that setting this in ThrottleStop will also be overridden by the EC.

Your screenshots show that you do not have Speed Shift Technology enabled yet. You have Speed Shift EPP checked on the main screen but this will not do anything. First you have to go into the TPL window and enable Speed Shift. After you do this, you should see SST in green on the main screen which confirms that Speed Shift Technology is enabled. This probably will not make any difference to your power limit problem but it might help with overall responsiveness.

I was going to suggest to keep your eyes open for a cheap C930 on eBay but there is nothing cheap about their price. Maybe too many people know what the 930 is capable of after some power limit tweaking.
Did what you said. Switched to the newest (beta) version (9.2.9). Set FIVR Disable and Lock Turbo Power Limits, with Turbo Boost Power Limit (Long/Short) at 28/30 and locked. PP0 is at 100. Undervolted to -80.1 (CPU Core + CPU Cache). TDP Level checked and set to 0. Speed Shift enabled and Speed Shift EPP checked (I see the green SST now) and set to 32.

However, I still experience throttling to 18.8W after the initial 28 seconds of short turbo (aka. PL2 for the first half minute, then PL1). I see that you indicate that I might just have to live with it. But I still think it is really weird that I was able to increase the short turbo, but the long turbo still seems to be controlled by something else (maybe the... EC, as you say? or the Intel Dynamic Platform and Thermal Framework?).

Intel gave the 8250U CPU a 15W TDP limit.
Yeah, I saw that. Still, mine seems to be 18.8W for some reason. Idk why that would be.

Should I just give up, and stop spending time on this?
 

unclewebb

ThrottleStop & RealTemp Author
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mine seems to be 18.8W for some reason
It is typically the EC that enforces these hard limits and it is usually the long term limit that gets enforced. A manufacturer can choose to set this equal to the TDP (15W), or they can set this limit to 18.8W or whatever number they like. This can vary from one manufacturer to the next. Are you getting stuck at 7.5W anymore? The Disable and Lock option usually prevents this.

Should I just give up, and stop spending time on this?
No one has come up with a solution for power limit throttling that is enforced by the EC.
 

adrianpip2000

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It is typically the EC that enforces these hard limits and it is usually the long term limit that gets enforced. A manufacturer can choose to set this equal to the TDP (15W), or they can set this limit to 18.8W or whatever number they like. This can vary from one manufacturer to the next. Are you getting stuck at 7.5W anymore? The Disable and Lock option usually prevents this.


No one has come up with a solution for power limit throttling that is enforced by the EC.
Thanks for your reply! I guess I'll just live with it then. As a side note, what does EC actually stand for? I've just assumed it's some kind of hardware or BIOS level thing.
 

unclewebb

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what does EC actually stand for?
An EC is an embedded controller. It takes input from a variety of sensors and gets to decide the power limits for your CPU. It all works good until a 5 cent sensor craps out. Then your laptop might get magically locked in to 7.5W mode or worse. I have seen some Dells get locked at 0.0W which results in constant power limit throttling down to 800 MHz regardless of load. Fun times when that happens. I have a 13 year old laptop collecting dust in my closet that runs way faster than that.
 

adrianpip2000

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An EC is an embedded controller. It takes input from a variety of sensors and gets to decide the power limits for your CPU. It all works good until a 5 cent sensor craps out. Then your laptop might get magically locked in to 7.5W mode or worse. I have seen some Dells get locked at 0.0W which results in constant power limit throttling down to 800 MHz regardless of load. Fun times when that happens. I have a 13 year old laptop collecting dust in my closet that runs way faster than that.
Huh, interesting (and annoying)! Thanks anyway, I see you're helping a lot of people here on the forum! Hope you have a good evening/morning/day!
 
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