# Undervolting a HP OMEN-15



## apheliosmain (Oct 20, 2021)

Hi,
Im running on a HP OMEN-15, i79750h, gtx 1660 ti. It runs very hot so iv been playing around with throttlestop to lower the temps, ill attach few pictures of my undervolt and logs.  I have given up alot of performance for better temps, so if someone could help me get a better undervolt setting i would be grateful  But this undervolt seems decent and i can run games like overwatch, borderlands,league with decent fps and temps around 65~70 with league and 75~85 with overwatch and other games.  My problems are:

1.My rig tends to shut down automatically even if the temps are around 45~55. TS bench shows no errors. In Limit reasons there is sometimes PL1 under CORE in yellow and EDP under RING in yellow as well When i checked my logs I saw the POWER STATUS CHANGE and SUSPEND and didnt have the faintest idea what they meant.

2. I feel like i have giving up too much performance for temps so it would be really appreciated if someone could give me setting where i can run games with better fps and similar temps :v

ANY HELP IS APPRECIATED


----------



## mql (Oct 20, 2021)

I cannot say that this is your decision. In my case, UEFI unlocking helped for Lenovo IdeaPad L340 (CPU i7-9750H) and change the "System Time and Alarm Source" parameter from "ACPI Time and Alarm Device" to "Legacy RTC".



> 0xD7B66     One Of: System Time and Alarm Source, VarStoreInfo (VarOffset/VarName): 0x54A, VarStore: 0x1, Size: 0x692, Name: Setup, QuestionId: 0xC08, Size: 1, Min: 0x0, Max 0x1, Step: 0x0 {05 91 5F 10 60 10 08 0C 01 00 4A 05 10 10 00 01 00}
> 0xD7B77         One Of Option: ACPI Time and Alarm Device, Value (8 bit): 0x0 (default) {09 07 61 10 30 00 00}
> 0xD7B7E         One Of Option: Legacy RTC, Value (8 bit): 0x1 {09 07 62 10 00 00 01} (changed to)



This stopped the power decrease while the computer was running.
Symptoms of the problem: the computer started up with one setting, and after a while the settings were changed to lower than initially.


----------



## apheliosmain (Oct 21, 2021)

Will do. Also can anyone explain this?


My rig restarted and when i opened throttlestop limit reasons ans it was full of theses stuff :v 
anyone got any ideas what this is?


----------



## unclewebb (Oct 21, 2021)

When booting up or resuming from sleep, it is normal for some of the throttling reasons to be triggered in ThrottleStop. This seems to happen before the CPU has been fully setup. You only need to be concerned when you see boxes glowing red in Limit Reasons. A red box means throttling is in progress. 

Some laptops will show constant POWER STATUS CHANGE messages in the log file every 5 seconds. This can happen when the laptop battery is only being charged to 70%. I am not a big fan of battery saving software so I turn this stuff off and always charge my laptop battery to 100%. You can also see these messages when you enter and resume from sleep and there are probably a few more reasons why these messages can show up in the log file. 

I recommend checking the MMIO Lock box. The MMIO PL1 power limit is set to only 40W. That means your 75W MSR PL1 power limit is being ignored. 



apheliosmain said:


> My rig tends to shut down automatically


Did you test your undervolt at the reduced CPU speed that you are using? An undervolt that is 100% stable at 4000 MHz might not be 100% stable when you drop your turbo ratios to 26 and run your CPU at 2600 MHz. A computer should not be randomly shutting down. There is either a problem with your battery or power adapter or your voltage is set too low. I would set the Intel GPU and iGPU Unslice back to +0.0000. If you are using a Nvidia GPU when gaming, lowering the voltage of the Intel GPU can cause stability problems without saving any meaningful amount of power. It is not worth risking stability.

Set the core and the cache to -100 mV and test to make sure your computer is 100% stable without any random shut downs. If you are stable, then you can start bumping the core offset further in steps of -25 mV.


----------



## apheliosmain (Oct 23, 2021)

Thank You for giving such a detailed explanation, I set the turbo ratios back to 4000 MHz and checked the MMIO Lock box. Checking the Lock box erased the PL1 and PL2 problems but setting the turbo ratios to 4000 MHz did not help the temps, while running TS Bench at 120M it reached 90+, in Limit Reason Thermal under Core and EDP other under RING started blinking to red. I am planning to reapply thermal paste but I want to find a sweet spot in Throttle stop where I get decent performance and I don't have to be scared to burn my fingers when I touch my laptop ._.


----------



## unclewebb (Oct 23, 2021)

apheliosmain said:


> in Limit Reason Thermal under Core and EDP other under RING started blinking to red.


It is rare for a laptop with a 9750H to be able to run a full load stress test at full speed without it overheating and thermal throttling. Almost every major manufacturer is guilty. The inadequate cooling that is used means they either thermal throttle or they power limit throttle to try and prevent thermal throttling. Either way you end up losing out on maximum performance. 

If your cooling system cannot handle cooling your CPU at 75W then consider reducing PL1 to 60W or less. If the cooling system cannot handle running at 90W for 28 seconds then you need to either reduce the PL2 power limit or reduce the turbo time limit or reduce both.

The other thing you can do is reduce the CPU speed. The heat problem is not when the CPU is lightly loaded so try staggering the turbo ratio limits. That way you are not sacrificing as much performance when lightly loaded.



 

It is a balancing act no matter what CPU control method you choose. Whatever works best. 
You might have to buy an external keyboard and mouse so you do not get any third degree burns.


----------



## apheliosmain (Oct 24, 2021)

I set the turbo limits as you told me to, I also set the undervolt as such:
Core - 160.2
Cache - 100.6
iGPU - not undervolted
TPL
PL1 - 75
PL2 - 80
Turbo Time Limit - 28
If its not too much trouble could you tell me what values I should keep in PL2 power limit and also what value I should keep in Turbo Time Limit?
I do use an external mouse and keyboard its just whenever I try to clean my laptop I can feel how it is.


----------



## unclewebb (Oct 24, 2021)

apheliosmain said:


> what values I should keep in PL2 power limit and also what value I should keep in Turbo Time Limit?


Here are some questions to ask yourself when trying to come up with some appropriate power limits.

Can your cooling handle your CPU running indefinitely at 75W without overheating? If your cooling cannot handle this then I would suggest lowering the long term PL1 turbo power limit to what your cooling can handle. 

Next question. How long can your computer run at 80W without it overheating? This is what you need to set the PL2 power limit to. If your cooling can handle 80W but only for 4 seconds then setting the turbo time limit to the default 28 seconds is way too much. This amount of time is too much for most laptops because of inadequate cooling. 

Adjust away. Some people do not mind a little bit of thermal throttling. It is not going to hurt your CPU. Thermal throttling is specifically designed to keep your CPU at a safe temperature. 

Other people prefer a little bit of power limit throttling so their CPU never reaches the thermal throttling temperature. Whatever you decide is up to you. There is no best setting for everyone and every laptop.


----------

