# Undervolting Y540 (i7-9750H)



## t0bler0ne (Feb 5, 2021)

Hello,

I've been reading this forum these days, and after a good clean and repaste I decided to try ThrottleStop to avoid ovearheating. I never cared too much about this, because I always assumed it's a laptop, but since last week my laptop started to underperform a little bit (I never undervolted this laptop since I bought it).

I ran a Cinebench R20 test and I got 3074 points (keeping best score). But while Cinebench is stress testing, I get this (I attached images, but specifically PL1 and EDP OTHER in red, and THERMAL turns to red sometimes too). I'm just wondering if I did this well and if this is fairly normal?

So far, I'm pretty satisfied with the results. While playing Red Dead Redemption 2 (a pretty demanding game) I get 70 fps and between 65-70 degrees (celsius). But I'm not sure why I'm getting those red signs. Strangely enough, according to HWiNFO, it doesn't throttle (power limit, package ring, thermal, etc.).

Also, when I set -120 v in the CPU offcore setting before going down to -200, I was getting 38-40º in idle temps (by idle I mean when I'm basically doing nothing, just posting this for example - correct me if I'm wrong). Now it's between 40-45º. But I guess it's just common sense, because I was expecting good performance for games as well, so I can't have both. And 70º while heavy gaming is pretty decent, I think.

I'm sorry if it's a stupid thing to ask, I literally have no idea about this stuff until I read a little bit about it here and learned how to do all that thanks to unclewebb and other users reporting their settings.

Thank you.


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## unclewebb (Feb 5, 2021)

When using ThrottleStop Limit Reasons, do not run HWiNFO at the same time. HWiNFO clears the throttling information out of the CPU before Limit Reasons has a chance to correctly report it.

A 9750H is a powerful CPU that runs hot. If you increase the turbo power limits in the TPL window, you can get rid of the PL1 power limit throttling that is shown in your screenshot above. Instead of power limit throttling, now your CPU will run hotter and you will start to see THERMAL throttling instead. It tends to be one or the other. The 9750H is a lot of CPU power packed into a laptop case. 

All of your ThrottleStop settings look appropriate. In the Options window, the Intel default value for PROCHOT Offset is 0. This tells the CPU to begin thermal throttling at 100°C. Some laptops set this offset value to 2 or 3 so the CPU starts to throttle a little sooner at 98°C or 97°C. Lenovo has set this to 6 so your CPU starts to thermal throttle at 94°C instead of the full 100°C that Intel says is fine. This setting is not locked so consider reducing the PROCHOT Offset value so your CPU starts to throttle at a little higher temperature.

If you decide to change PROCHOT Offset, after you have found an appropriate offset value, I would also use the Lock PROCHOT Offset option just to make sure this value does not change.

Use TS 9.2.9. It is stable and has some new features. 









						ThrottleStop 9.2.9
					

ThrottleStop 9.2.9 https://www.techpowerup.com/download/techpowerup-throttlestop/  New Features - added 10850K / 10900K support including a new Turbo Group access window. - updated the TS Bench and the C State window for the 10 core CPUs. - enabled Limit Reasons support for Comet Lake CPUs. -...




					www.techpowerup.com


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## t0bler0ne (Feb 5, 2021)

unclewebb said:


> When using ThrottleStop Limit Reasons, do not run HWiNFO at the same time. HWiNFO clears the throttling information out of the CPU before Limit Reasons has a chance to correctly report it.
> 
> A 9750H is a powerful CPU that runs hot. If you increase the turbo power limits in the TPL window, you can get rid of the PL1 power limit throttling that is shown in your screenshot above. Instead of power limit throttling, now your CPU will run hotter and you will start to see THERMAL throttling instead. It tends to be one or the other. The 9750H is a lot of CPU power packed into a laptop case.
> 
> ...


Ah, I see. I guess I'll just check temps with ThrottleStop then. I will also check the new version.

Sorry for the dumb question, but when you say increasing the turbo power limit, you mean the turbo time limit that is set to 28, or both long and short power? Do you think it would safe to increase more than 70 and 107? I think both were the default settings if I recall correctly. Or should I just leave it like that?

The PROCHOT Offset settings was a really confusing concept to me but now I think I understand what it does. That's why it keeps throttling when I run Cinebench. I guess PROCHOT Offset to 3 would be safe. Wouldn't 0 be a little bit dangerous though? It means that it wouldn't throttle and it woudn't shut down the system even if it's literally toasting, right? Well, even if those red signs keep appearing, I guess it can't be worse than before. I played games under 95° for 2 years.

Thank you so much for your help, I really appreciate it.


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## unclewebb (Feb 6, 2021)

t0bler0ne said:


> when you say increasing the turbo *power* limit, you mean the turbo *time* limit that is set to 28


Why would I tell you to increase the power limit if I really meant to say the time limit? If I say power, I mean power.

Some Lenovo laptops have hard locked the long term turbo power limit to 70W. Setting this to 75W or 80W in ThrottleStop might not make any difference. It never hurts to try. Watch Limit Reasons or run a log file to watch for any throttling. See if PL1 power limit throttling is reported at 70W or 75W. 

Your CPU has a TDP rating of 45W. Your laptop manufacturer has already set the power limit well above the rated TDP. They seem confident. Whether you set this to 70W or try to increase this to 75W or 80W is not going to make any significant difference. 



t0bler0ne said:


> Wouldn't 0 be a little bit dangerous though?


The Intel default for PROCHOT Offset is 0. Intel is not in business to lose money. Why would they set the thermal throttling temperature to 100°C if they knew that doing this was going to be dangerous? No company would do that. 

Trust Intel. They know their CPUs can run reliably at up to 100°C. I recently bumped the throttling temperature of my desktop CPU up to 105°C. It continued to run while thermal throttling at this temperature. The motherboard allows me to go as high as 115°C. Now that is getting a little closer to dangerous. 





For reference, the default Intel shut down temperature is usually not until 125°C. That limit is designed to protect the CPU from damage.


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## t0bler0ne (Feb 6, 2021)

unclewebb said:


> Why would I tell you to increase the power limit if I really meant to say the time limit? If I say power, I mean power.
> 
> Some Lenovo laptops have hard locked the long term turbo power limit to 70W. Setting this to 75W or 80W in ThrottleStop might not make any difference. It never hurts to try. Watch Limit Reasons or run a log file to watch for any throttling. See if PL1 power limit throttling is reported at 70W or 75W.
> 
> ...


Alright, will just leave it to 70. Turbo Boost Short Power to 90 seems to work fine too.

I set the PROCHOT Offset to 3 though. Offset to 0 made my computer shutdown. I know it's not dangerous anyway, but this shit gives me heart attacks.


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## unclewebb (Feb 7, 2021)

@t0bler0ne - The Intel thermal shut down temperature is 125°C. Some laptop manufacturers have decided to ignore Intel's advice and are using their own shut down temperature. This is typically set to 100°C. That is a mistake on their part. They should read the Intel docs. When a manufacturer does this, you are forced to use a PROCHOT Offset value of 3 or 4 to avoid ever hitting 100°C.

The Intel design gives a CPU 25°C of headroom between thermal throttling and thermal shut down. This is done deliberately so there is zero chance of an unintended shutdown. Lenovo's decision to redesign something that works great gets a big thumbs down.


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## t0bler0ne (Feb 7, 2021)

unclewebb said:


> @t0bler0ne - The Intel thermal shut down temperature is 125°C. Some laptop manufacturers have decided to ignore Intel's advice and are using their own shut down temperature. This is typically set to 100°C. That is a mistake on their part. They should read the Intel docs. When a manufacturer does this, you are forced to use a PROCHOT Offset value of 3 or 4 to avoid ever hitting 100°C.
> 
> The Intel design gives a CPU 25°C of headroom between thermal throttling and thermal shut down. This is done deliberately so there is zero chance of an unintended shutdown. Lenovo's decision to redesign something that works great gets a big thumbs down.


Yeah I was kinda surprised when my computer shut down. Maybe it has to do with my laptop's last BIOS update (which was released in January), but who knows. At least undervolting options aren't locked.

Hey @unclewebb may I ask you a question, if you don't mind?

I was messing with CR20 again to test turbo ratio limits to lower thetemperatures. But I set the ratio limits back to default (45, 44, etc) before stress testing CR20 again. Problem is, I noticed that in TS the clock is not on full speed while stress testing Cinebench; it's running at 3800 mhz more or less with the PGK power reaching 70W (so turbo power limits is unlocked). I'm sure that it reached at least 3950 mhz before (FID close to 40, now it's 38). It doesn't even reach 3000 points now. THERMAL in red is showing and HOT too. I thought it was weird because there's enough power (it's not locked to 45W), so my question is, did I ruin the thermal paste or something? Idle temps around 45º now. Gaming seems normal, reaching no more than 80º after 30 minutes. I haven't touched anything besides ratio limits but I doubt that has anything to do with full clock speed. Forgot to mention, when idling,


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## unclewebb (Feb 8, 2021)

t0bler0ne said:


> did I ruin the thermal paste or something?


Does the FIVR monitoring table show that your undervolt is still being applied to the CPU?

Some thermal pastes have a short life span when run at over 90°C. Thermal performance can degrade in a week or two at these temperatures. Noctua NT-H2 thermal paste gets a lot of thumbs up from users on Amazon and on this forum.


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## t0bler0ne (Feb 8, 2021)

unclewebb said:


> Does the FIVR monitoring table show that your undervolt is still being applied to the CPU?
> 
> Some thermal pastes have a short life span when run at over 90°C. Thermal performance can degrade in a week or two at these temperatures. Noctua NT-H2 thermal paste gets a lot of thumbs up from users on Amazon and on this forum.


Yeah, the undervolt settings are being applied (see pics).

As you can see, those temps are really unstable while stress testing (not unstable when idle though, every FID column has the almost same temp, between 42-43). I guess I ran too many CR20 tests and somehow the thermal paste got wasted. I brought my laptop to a local store last week for a good clean and repaste. But I'm sure the thermal paste was a crappy one. I didn't expect to get wasted so soon as bad as it may be. Probably time to buy the NT-H2 and play games limiting turbo ratio limits in the meantime.


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## unclewebb (Feb 8, 2021)

t0bler0ne said:


> I brought my laptop to a local store last week


Your screenshot shows why I would never trust someone else to re-paste my CPU. I want to know what paste is used and whether it was applied properly.

I have heard reports that some pastes literally do not last a week at high temperatures. They work great day one but within a week, temperatures are going up and up and the job needs to be redone.

When a CPU is idle, power consumption should be minimal. A good paste job or a bad paste job will not be noticed at idle. Hard not to notice a bad thermal paste job when THERMAL is glowing red during a full load test.


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## t0bler0ne (Feb 8, 2021)

unclewebb said:


> Your screenshot shows why I would never trust someone else to re-paste my CPU. I want to know what paste is used and whether it was applied properly.
> 
> I have heard reports that some pastes literally do not last a week at high temperatures. They work great day one but within a week, temperatures are going up and up and the job needs to be redone.
> 
> When a CPU is idle, power consumption should be minimal. A good paste job or a bad paste job will not be noticed at idle. Hard not to notice a bad thermal paste job when THERMAL is glowing red during a full load test.


Yeah, it was a waste of money, but I don't have the guts to do it myself, I'm really bad with these things and the idea of opening a laptop terrifies me.

It's a relief somehow to know the cause, because I was going nuts with all the points below 3000.


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