# No option to undervolt my cpu or gpu?



## Blohsh (Jul 13, 2021)

Hello there, i see many tutorial on the internet to undervolt cpu, with throttlestop, but i don't see those options for me. they are not there. My processor core2duo p8400, Machine: Dell Precision M6400


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## unclewebb (Jul 13, 2021)

ThrottleStop supports your CPU.  Post screenshots if you need help.

Edit - You need to use the Windows High Performance power plan so Windows and ThrottleStop do not interfere with each other. Set the multiplier to the maximum, adjust the voltage on the main screen, click on the Turn On button so it does not say Monitoring in the title bar. Make sure EIST (SpeedStep) is enabled. 

These older CPUs do not use the FIVR so most of the internet guides do not show how to undervolt the Core 2 Duo CPUs.


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## Blohsh (Jul 14, 2021)

unclewebb said:


> Reply:


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## unclewebb (Jul 14, 2021)

Try checking SLFM. I think 0.95 V is only available when SLFM is enabled.


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## Blohsh (Jul 21, 2021)

unclewebb said:


> Reply:


It is making laptop unstable/ freezes or restarts. Tried different values only worked at 1.8 something V.


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## unclewebb (Jul 21, 2021)

Blohsh said:


> 1.8 something V.


Do you mean 1.08V?

1.80 V would be way too much and not possible.

A P8400 is a low end CPU. It might not have much room for undervolting. It is not a high performance T series CPU. If your computer is not stable then you need to increase the voltage. Not every CPU is great at overclocking or undervolting.

What is the default maximum VID voltage that ThrottleStop lets you set? Many of these CPUs have a default VID voltage somewhere around 1.20 V.


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## Blohsh (Jul 23, 2021)

unclewebb said:


> Do you mean 1.08V?
> 
> What is the default maximum VID voltage that ThrottleStop lets you set?


Oops, that was 1.0875. 
the max throttlestop can let me set is 1.2500V
My processor have  VID Voltage Range  1.050V-1.150V
i've test 1.050V it freezes, on 1.150 it freezes, had to force shutdown.
what value should i set?


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## unclewebb (Jul 23, 2021)

Blohsh said:


> on 1.150 it freezes


If your computer is freezing at 1.150 V then it needs more voltage. Try 1.200 V. If that is OK, try 1.175 V.

1.200 V is a 50 mV undervolt. 1.175 V is a 75 mV undervolt. An undervolt range of 50 mV to 75 mV is the normal range for many Intel CPUs. Intel uses a little bit of extra voltage to guarantee long term stability. Your CPU is 12+ years old. The amount of undervolt head room available is going to be limited.

There is very little to be gained by undervolting a CPU that does not consume a lot of power. If it runs too hot, replace the thermal paste. Your temperatures look fine.


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