# How can I undervolt my old pentium processor?



## Pwkepkw (Jul 24, 2019)

Acer Aspire/Pentium T3200

I was using 'Throttlestop' on Windows in order to undervolt my cpu. But I couldn't find any alternative which works on BSD/Linux. I tried several tools from Github but they didn't work too.

I got some numbers from the throttlestop.ini file but don't know how to use them:
Options1=0x8010088C
Payload1=0xC18

Options2=0x80100880
Payload2=0x613


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## Pwkepkw (Jul 25, 2019)

I saw that there is a tool called 'cpucontrol'. I guess I can override default msr numbers with it, but I don't know how to use it nor didn't understand the manual. I will be glad if anyone help a bit.
I had tried intel-undervolt both on linux and freebsd but they both gave I/O error, so I think my pc has a different location of that msr number which controls voltage.


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## k.jacker (Jul 25, 2019)

I don't know how much cpucontrol(8) can do, but I guess if it can change VIDs, you'll most likely have to read a lot CPU specific documentation before you figure out how to get right information from your CPU and write your changes back.
I also doubt cpucontrol(8) is ment to be an end-user tool like for example powerd(8).

What has worked well for me on several Core Duo T2x00 (almost same CPU, previous generation, but 32bit only) was to hardwire a specific voltage (VID) to all frequencies (FID) by the help of pinmodding. That's maybe to much of a hassle on a laptop, but it works well and is fun. Pingrid layouts should still be available if you just search the www.

I spent a lot of time on that topic, years ago, but never managed to understand all of it. As you seem to be new to this, I'd say it's much easier to learn how to pinmod, than to understand CPU internals and cpucontrol(8).


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## Pwkepkw (Jul 25, 2019)

k.jacker said:


> I don't know how much cpucontrol(8) can do, but I guess if it can change VIDs, you'll most likely have to read a lot CPU specific documentation before you figure out how to get right information from your CPU and write your changes back.
> I also doubt cpucontrol(8) is ment to be an end-user tool like for example powerd(8).
> 
> What has worked well for me on several Core Duo T2x00 (almost same CPU, previous generation, but 32bit only) was to hardwire a specific voltage (VID) to all frequencies (FID) by the help of pinmodding. That's maybe to much of a hassle on a laptop, but it works well and is fun. Pingrid layouts should still be available if you just search the www.
> ...



This program worked well on Windows. Isn't there a way to look up which MSR registers it actually changes? Thanks for letting me know about pinmodding but I prefer not to touch hardware at all, even if it means I will go back to Windows.









						ThrottleStop (9.5) Download
					

ThrottleStop is a small application designed to monitor for and correct the three main types of CPU throttling that are being used on many lapto




					www.techpowerup.com
				




I have the ini file, but it doesn't say anything about MSRs. The numbers don't have any meaning either.


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## rigoletto@ (Jul 26, 2019)

This can usually be done at BIOS/UEFI.


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