Strange ThrottleStop behaviour...

[potatopie]

Hi,

This is not really a problem, but something I cannot understand and it's bugging me. I had problems with CPU throttling while gaming on my Lenovo 530s(Intel Core i5-8250U) at around 70C. So I started researching on ThrottleStop. I check CPU temp and clock with MSI Afterburner RTSS overlay while playing. Here is what is weird:

When I open ThrottleStop without changing any settings whatsoever, and just let it run, no throttling occurs. Why??? It is not on(green tray icon). My power settings are set to best performance, while plugged in.

If I do the same thing while unplugged, power settings are set to best performance, ThrottleStop does not seem to have any affect(it's throttling as expected).

If it's not enabled(just stays open), how can it stop CPU from throttling? I must mention I have disabled C1E and SpeedStep in program settings yesterday(but turned them back on later). I have reinstalled Windows and reset BIOS to defaults just in case this morning. Logically, if changing these settings affected CPU somehow, why everything is throttling ONLY when program window is not active? So I doubt fiddling with these setting was the cause.

I am happy that it stops throttling. I just cannot understand why it does, when I have not explicitly let it to.

 

[phanbuey]

Hi...

can you check these settings?

Are you running throttlestop as admin?

How to manage Power Throttling on Windows 10

Power Throttling is a feature to improve battery life on Windows 10, but when it doesn't work as expected, you can use this guide to manage its settings.

www.windowscentral.com

 

[unclewebb]

When ThrottleStop first starts up, if it sees some obvious problems, it makes a few changes to try to help out. Most users are happy with this. Not too many complaints.

Without seeing some screenshots or knowing what your throttling problem is, it is hard to say exactly what is going on. I wrote the code over the last 10 years so some of the details are a mystery even to me. Just be happy that ThrottleStop is there to help.

Here is an 8th Gen low power U CPU running way beyond its 15W TDP spec with the help of ThrottleStop.

 

[potatopie]

Ok I ran that test and peak temp at which it would turn on throttle was around 79C in all three tests. The throttling problem I had in games would happen around 70 or as low as 65. My suspicion is now that it it is somehow related to Nvidia MX150 (it's disabled during non 3D use, Nvidia Optimus setup) running at same time and contributing to overall heat... And yet, with ThrottleStop open in background(doing nothing, no settings changed or applied), I would see temps go up to 78 in intensive spots and no throttling would happen. Does it mean having ThrottleStop open in background could potentially fry my laptop? I understand it software to use for your own risk, but it's weird it changes throttling behaviour just by staying open. Here is screenshot of tests. I could screenshot game but not sure there is a point because it heats up gradually over time, I see temp go up and down during gameplay.

You have mentioned ThrottleStop makes changes when it first starts up? What sort of changes?

Hi...

can you check these settings?

Are you running throttlestop as admin?

How to manage Power Throttling on Windows 10

Power Throttling is a feature to improve battery life on Windows 10, but when it doesn't work as expected, you can use this guide to manage its settings.

www.windowscentral.com

No, I'm not running it as admin. UAC kicks in, I click Yes.

As per article, my power settings were already set to Best performance. I have monitored the task manager power throttling, then when throttling occured(from 3400 down to 1600), it did not say throttling enabled. All programs show as throttling disabled.

 

[unclewebb]

In your example, the throttling you are seeing is being caused by the PL1 power limit. When this type of throttling is triggered, the EDP OTHER will also light up in red at the exact same time. PL1 stands for the long term turbo power limit. Intel tells manufacturers that they should set this equal to the TDP power limit. The Core i5-8250U has a 15 Watt TDP limit according to Intel. You can click on the TPL button and see what turbo power limit values your CPU has been set to by Lenovo.

Intel® Core™ i5-8250U Processor (6M Cache, up to 3.40 GHz) Product Specifications

Intel® Core™ i5-8250U Processor (6M Cache, up to 3.40 GHz) quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.

ark.intel.com

ThrottleStop is reporting that your CPU Package (PKG) Power is at 14.8 Watts. The CPU is being automatically slowed down so power consumption does not exceed 15 Watts. That is how throttling works. Your laptop is working exactly as intended.

I would see temps go up to 78 in intensive spots and no throttling would happen.

Most modern CPU throttling is power related. It is rarely triggered by a specific temperature.

In the ThrottleStop Options window you can turn on Nvidia GPU monitoring. In the Options window you can also check, Add Limit Reasons to Log File. Press OK and go back out to the main screen and check the Log File option. Go play a game or whatever and when you are finished testing, exit ThrottleStop and it will create a log file of your CPU performance. This log file with today's date on it will be stored in the ThrottleStop / Logs folder. Now you will have a complete record of what speed your CPU was running at, its temperature, the Nvidia GPU temperature, power consumption and what sort of throttling was going on. The log file will tell a very complete story of your CPU performance. You can attach it here if you want me to tell you what it all means.

Does it mean having ThrottleStop open in background could potentially fry my laptop?

I think you are worrying too much. ThrottleStop has been around for years. Do some Google research. Lots of happy users and it is going to be close to impossible to find someone that has fried their laptop because of ThrottleStop.

Your screenshot shows that your CPU is running within its 15 Watt TDP limit just like Intel and Lenovo intended. Running ThrottleStop is not forcing your CPU to do anything that it was not designed to do. Definitely nothing crazy or in any way dangerous. Desktop 8th Gen CPU owners push 10 times that many watts through their overclocked CPUs without failure.

Now compare my screenshot to your screenshot. 3691 MHz is a 58% performance improvement compared to 2335 MHz. In my screenshot, thermal throttling has just started to kick in to save the processor from any long term damage. No worries. Some users prefer slow and cool. I prefer hot and fast. ThrottleStop can be adjusted so you can decide what you prefer.

If you are not interested in maximizing your CPU performance then delete ThrottleStop from your computer. When properly setup and cooled, the low power 8th Gen U CPUs have a lot of potential. They can perform some tasks similar to a fast 4th Gen desktop CPU.

You have mentioned ThrottleStop makes changes when it first starts up? What sort of changes?

Sometimes the bios does not properly setup a CPU. For one example, some registers that control the CPU speed are supposed to contain the same value for each core. If ThrottleStop sees any inconsistencies, it will automatically correct problems like this.

You can make your CPU run faster and cooler by using ThrottleStop. That is all most users care about. The whys may be interesting to some but ultimately, not that important.

 

[potatopie]

Hi, here are some logs monitoring CPU from ThrottleStop:

2019-06-22 18:35:00 33.09 23.4 100.0 100.0 0 72 1.0743 15.1 PL1
2019-06-22 18:35:01 33.38 22.6 100.0 100.0 0 73 1.0291 14.7 PL1
2019-06-22 18:35:02 33.58 22.6 100.0 100.0 0 73 1.0198 14.8
2019-06-22 18:35:03 33.42 22.8 100.0 100.0 0 75 1.0781 15.2
2019-06-22 18:35:04 33.57 22.7 100.0 100.0 0 71 1.0709 14.7
2019-06-22 18:35:05 33.42 22.9 100.0 100.0 0 72 1.0988 15.1
2019-06-22 18:35:06 33.08 22.7 100.0 100.0 0 74 1.0747 15.0
2019-06-22 18:35:07 33.60 22.2 100.0 100.0 0 71 1.0450 14.8
2019-06-22 18:35:08 33.54 22.6 100.0 100.0 0 73 1.0491 15.2 PL1
2019-06-22 18:35:09 33.21 23.1 100.0 100.0 0 73 1.0625 14.9 PL1
2019-06-22 18:35:10 33.48 22.4 100.0 100.0 0 75 1.0250 14.9
2019-06-22 18:35:11 33.16 22.8 100.0 100.0 0 73 1.0530 14.9 PL1
2019-06-22 18:35:12 33.38 22.8 100.0 100.0 0 71 1.0485 14.8
2019-06-22 18:35:13 33.39 23.0 100.0 100.0 0 72 1.0807 15.1
2019-06-22 18:35:14 33.17 22.6 100.0 100.0 0 75 1.0598 14.8 PL1
2019-06-22 18:35:15 33.41 22.7 100.0 100.0 0 73 1.0536 15.1 PL1
2019-06-22 18:35:16 33.24 22.9 100.0 100.0 0 71 1.1024 14.7
2019-06-22 18:35:17 33.32 22.5 100.0 100.0 0 73 1.0764 15.0
2019-06-22 18:35:18 33.33 22.7 100.0 100.0 0 72 1.0825 14.9
2019-06-22 18:35:19 33.33 23.0 100.0 100.0 0 75 1.0873 14.9
2019-06-22 18:35:20 31.49 26.6 100.0 100.0 0 72 1.0135 15.5 PL1
2019-06-22 18:35:21 32.31 23.2 100.0 100.0 0 73 1.0604 14.6 PL1
2019-06-22 18:35:22 33.28 22.8 100.0 100.0 0 72 1.0647 14.8 PL1
2019-06-22 18:35:23 33.34 22.6 100.0 100.0 0 71 1.0853 14.9
2019-06-22 18:35:24 33.27 22.4 100.0 100.0 0 74 1.0742 14.8
2019-06-22 18:35:25 33.61 22.1 100.0 100.0 0 72 1.0997 15.1

It looks to me that throttling warning kicks in but it doesn't downclock?

And here is MSI Afterburner log without ThrottleStop running in the background:

As you can see it drops to 1600MHz at 74C... It is default behaviour on my system, and in all games. I am grateful you have explained how useful ThrottleStop is. I know that. What I am asking why ThrottleStop prevent my clock dropping from 3600 MHz to 1600 MHz if it stays open?

Your screenshot shows that your CPU is running within its 15 Watt TDP limit just like Intel and Lenovo intended. Running ThrottleStop is not forcing your CPU to do anything that it was not designed to do.

During maximum load, before "Throttle" kicks in, it's around 32 something. I understand that from stress test it may look like everything is working as intended. But why throttling stops while playing games?(see logs above).

 

[unclewebb]

But why throttling stops while playing games?

Without access to your computer, it is impossible to say. I would need to do some extensive testing to try to find out what register or registers your bios is not setting up correctly. Maybe it is something bad that Windows is doing. I just don't know. You will just have to accept that your laptop has a defect, likely by design. Many laptop models, from all of the major manufacturers, have similar problems and this has been going on for over a decade. This is why I wrote ThrottleStop.

It looks to me that throttling warning kicks in but it doesn't downclock?

The down clock in that graph where the CPU gets stuck at its minimum frequency is not how Intel designed normal thermal throttling or normal power limit throttling to work. Throttling is supposed to be as subtle as possible. The CPU is only supposed to slow down just enough so it does not exceed any temperature or power limit. Whatever throttling scheme that Lenovo dreamed up, it is wrong. Their engineers need to sit down and talk with Intel's engineers. The throttling that is happening on our Lenovo laptops shows a complete lack of understanding by their engineering team.

I have a love / hate relationship with Lenovo. This is not the only stupid thing they have done. What I love about Lenovo is that the stuff they do that irritates me is very easy to fix. I have access to a couple of Lenovo laptops so you could say that ThrottleStop has been specifically tweaked to deal with some of Lenovo's more common throttling methods. For you and I, that is a good thing.

In your log file, PL1 in the far right column indicates throttling. The game or task you are running on your computer is running right at the 15 Watt power limit. When it goes over this limit, throttling kicks in just a little to bring it back under this limit. This will go on indefinitely. This is how Intel power limit throttling works. Internally the CPU is being sampled and its speed is being adjusted hundreds of times per second to try to maintain as close as possible to the 15 Watt TDP limit. A sudden drop to 1600 MHz is not what Intel wants computers to be doing. When Intel hands out their Intel Inside stickers to manufacturers, they want the user experience to be as seamless as possible. They would prefer that any throttling that might be necessary should barely be noticed by the end user. This is obviously not the case for your laptop. Throttling to 1600 MHz is very noticeable.

If you were playing a more demanding game or running a more demanding test, the log file would show a steady column of PL1 throttling. In this situation, the constant reduction in CPU speed would be a lot more noticeable in the log file.

When posting log files, either click on the Attach files button or copy and paste the data to www.pastebin.com
This will maintain the log formatting so it will be easier on the eyes.

Are you ready to use ThrottleStop to undervolt your laptop to get the most out of it?