# Undervolting I7-8550u



## NotJordan (Jul 5, 2021)

Hi, on Throttlestop I am trying to undervolt my laptop (Dell Inspiron 7373 2 in 1) for cooler temps. I'm not too sure whether the values of the core and cache should be the same, since I have seen some videos saying they should be the same and some shouldn't. Right now I can either do -219.7 for core and -123 for cache, and my laptop runs fine. But then when I do like -125 on both core and cache. For both the temps are pretty much the same. Also, I'm not too sure what to put for C7s and TPL. I am on the latest version of Throttlestop 9.3 and a lot of forums are on Throttlestop 8.7 and they look a lot different. Also, what should I put for the System Agent. Youtubers have never discussed this value, and same with the intel gpu and igpu unslice. Should the intel gpu and igpu unslice be the same?


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## unclewebb (Jul 5, 2021)

A lot of users with the 8750H / 9750H and the 8300H / 9300H see improvements when setting the core higher than the cache. The best test to prove this is Cinebench R20.

https://www.techpowerup.com/download/maxon-cinebench/

-200 core, -125 mV cache usually outperformed -125 mV core, -125 mV cache.



NotJordan said:


> For both the temps are pretty much the same.


Watching the temperatures is a good way to prove if something is working or not. Here are three images of some testing a user sent me that convinced me that requesting different voltages can benefit some CPUs running some software.






						Cinebench Test.zip
					






					drive.google.com
				




Programs that use a high percentage of AVX instructions seem to show the biggest improvements. Most modern games use AVX instructions but most programs do not use them as much as 3D rendering software like Cinebench does.

Your U series CPU might not show any benefit. You will have to do some Cinebench testing on your computer. If you do not see any benefit then set these two offset voltages equally.

The Intel GPU and iGPU Unslice usually need to be set equally. Most users that have a Nvidia GPU do not bother undervolting the Intel GPU. There is little if anything to be gained. Same for the System Agent. Most people only undervolt the core and the cache and leave the other voltages at +0.0000. Only make adjustments if you can prove that the adjustment increases performance or decreases temperatures.

Many Dell laptops have locked out CPU voltage control. Make sure you are using ThrottleStop 9.3 or 9.3.1. Check to see if undervolting is available in the FIVR window. Your requested voltage values should show up in the FIVR monitoring table Offset column.

The 8550U runs a lot faster when a manufacturer leaves the turbo power limits unlocked. Most Dell laptops with this CPU are locked down.


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## NotJordan (Jul 5, 2021)

When i disable turbo it is around 30-40 idle and max 70 when playing but with turbo on my idle is around 50 and max is 100. I don't want my laptop to be that hot. Also how will i know if my undervolt is better or not. Would the score be higher if the undervolt is larger, or do i look at the temps to see which one is better?


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## unclewebb (Jul 5, 2021)

If you want to slow your CPU down, adjust the Speed Shift Max value lower. Using Disable Turbo reduces performance too much. 

Do some Cinebench testing. Higher Cinebench scores mean you are getting better performance. Also look at your temperatures. Lower temperatures are best. Accurate and repeatable test results are difficult when a is reaching 100°C. You might want to disassemble your laptop and replace the thermal paste.


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## NotJordan (Jul 5, 2021)

Also, I managed to get the undervolt for core to -220, if my score and temps are better with the core being higher, i might try keep going higher until the system crashes. Does the system agent, igpu and intel gpu values matter as well?

Also, if i am getting hot temps in game while turbo on, should i maybe limit the fps? Or should i make it run unlimited. On Minecraft (1.16) with turbo off I get max 100 with around 60, with turbo on, i get max 300 with around 77-80 degrees. Should i maybe limit it to the refresh rate or double? Since i'm on a laptop, i managed to overclock the refresh rate from 60-70.

Unclewebb, what should i adjust the speed shift value to? Right now, it is on 0, and i know the max is 255. With it on 0 and turbo it is around 3000 and max 4000, with it disabled it is 1700. Should i maybe limit it so the speed is around 2000-3000?



unclewebb said:


> If you want to slow your CPU down, adjust the Speed Shift Max value lower. Using Disable Turbo reduces performance too much.
> 
> Do some Cinebench testing. Higher Cinebench scores mean you are getting better performance. Also look at your temperatures. Lower temperatures are best. Accurate and repeatable test results are difficult when a is reaching 100°C. You might want to disassemble your laptop and replace the thermal paste.


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## unclewebb (Jul 5, 2021)

NotJordan said:


> Does the system agent, igpu and intel gpu values matter as well?


Keep testing. Try different values and see if anything improves. Most people only undervolt the core and the cache. 

-125 mV core, -125 mV cache is OK
-225 mV core, -125 mV cache might be the same as -250 mV core, -125 mV cache and this will be the same as -500 mV core, -125 mV cache.

The CPU will ignore any really big core voltage request.


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## NotJordan (Jul 5, 2021)

I did a test i got 1560 with turbo off and speed shift at 0, but max temps were at 99. Should i lower the speed shift value? What about the TPL. I havent changed anything but how should i configure it


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## unclewebb (Jul 5, 2021)

NotJordan said:


> max temps were at 99


If the CPU reaches 99°C with turbo boost off then you really need to disassemble your laptop, clean it and replace the thermal paste. 

There is no point in trying to make adjustments if your laptop has a serious overheating problem.


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## NotJordan (Jul 5, 2021)

No, 99 was with turbo boost on. With it off i get max 70-80. Also, i found out that with those values, i would get a BSOD when i try to change the speedshift value, but when i lower it, i can change the value


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## unclewebb (Jul 5, 2021)

The amount of undervolt that will work reliably changes depending on what speed you run the CPU at. A CPU requires a different amount of offset voltage at full speed compared to when turbo boost is disabled. 

Did you try leaving turbo boost on and lowering the Speed Shift Max value in the TPL window? That is the best way to control the CPU speed and temperatures. Set Speed Shift Max to 32 to run your CPU at 3200 MHz. That should be a good compromise. 

There is nothing wrong with running your CPU at 99°C. Intel says anything less than 100°C is a safe operating temperature.


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## NotJordan (Jul 5, 2021)

what should i make the min for speedshift. It says the min is 4 but the value for me is 1

and what about the turbo power limits section? What should i put long power pl1 short power pl2 and turbo time limit?

also if i change the speedshift max in tpl should i uncheck the box in the main interface or keep it at 0?

should i turn bd prochot on or off?

i did another cinench test with the max 32 and i got max temps of 99 and lowest 95, with both values at -125, and gpu values at -115. I'm going to keep trying to increase the core values until i reach the maximum

Right now with the same values as the earlier comment (-125), i am in a school meeting and on minecraft and the temps are just under 60 degrees. I guess since I'm running alot of processes and the temps are under 60 that is quite good right? This is with turbo on and max 32.


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## NotJordan (Jul 6, 2021)

@unclewebb can you please help me??

@unclewebb what should i put for the TPL and C7s? I tried looking on youtube but i couldn't find anything


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## unclewebb (Jul 6, 2021)

Set the power limits to whatever your cooling can handle. Your CPU is already hitting 99°C so there is no point in increasing the power limits unless you can improve the cooling.

For voltage, use as little as is needed to be stable.

Are the C states locked? Post a screenshot. If it says, Package C State - Locked then leave it as is. If the C states are not locked then I would set the request value to C10. Many laptops lock out the lower C states. ThrottleStop will show what C states your CPU is using when it is idle.



NotJordan said:


> should i turn bd prochot on or off?


If this is not causing a problem then leave it as is.



NotJordan said:


> what should i make the min for speedshift. It says the min is 4 but the value for me is 1


The minimum possible multiplier that the CPU can use is 4. Setting Speed Shift Min to 1 or setting Speed Shift Min to 4 will result in the CPU doing the exact same thing. Any request between 1 and 4 tells the CPU to use the minimum multiplier.



NotJordan said:


> should i uncheck the box in the main interface or keep it at 0?


On many computers, you do not need to check the Speed Shift EPP box on the main screen of ThrottleStop. The Windows power slider in the system tray can be used to change the Speed Shift EPP value. Move the Windows power slider back and forth with Speed Shift EPP not checked in ThrottleStop. Look in the FIVR monitoring table to see what Speed Shift EPP values the CPU is using. Windows typically sets EPP to 84 when the slider is moved all the way to the right for Best Performance. That is a good setting for most laptops.

If the Windows power slider is not able to control Speed Shift EPP, then you can check this box on the main screen of ThrottleStop to control EPP.

Play around with ThrottleStop. Get to know the program. Watch some YouTube videos and search the forum here on TechPowerUp. You do not have to learn everything about ThrottleStop in one day.


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## NotJordan (Jul 6, 2021)

this is what ive done after what you said so is this fine?

also i found another video and they recommended to put the cache half of the core and its working quite well. Ive managed to get -250 and -125 with no problems so far and the temps are actually at 85 now which is good.


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## unclewebb (Jul 6, 2021)

Your Package C State Limit shows that it is Locked. Set the Request value to C7s. The BIOS has set this to C7s so there is no point in requesting a different value if this setting is locked. 

Have a look in the Task Manager Details tab. Some background tasks are unnecessary and can be eliminated. Try to increase the percent of time your CPU spends in the C7 state when your computer is idle. Windows is very efficient when setup correctly.


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## NotJordan (Jul 7, 2021)

@unclewebb what does the non turbo ratio mean in FIVR and what should i set it to? The max number i could go was 20 but does it make a difference to the temps?




what should i put for the cache ratio as well? does it make a performance or temp difference?






this is my turbo ratio limits. The lower i put it, the lower the temps but then i lose performance, so should this be fine or should they all stay at 32


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## unclewebb (Jul 7, 2021)

NotJordan said:


> non turbo ratio


This setting is not used if Speed Shift is enabled. Leave it as is.



NotJordan said:


> does it make a performance or temp difference?


Make adjustments, do some testing and find out if the adjustments you made provide any benefit. I prefer to set the turbo ratios to their default values. Some people prefer to lower them so their computer runs cooler but slower. Find a setting that you are happy with.


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