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Undervolt 3rd gen mobile i5/i7 CPUs?

Hello, with the unfortunate loss of the notebookreview forums, I seem to have trouble finding out definite answer to this. I currently undervolt my GTX 1070 and i7-7700HQ on my entertainment laptop using MSI Afterburner and Throttlestop.

 

I have tried Intel XTU but I hated how buggy they were.

 

My work laptop is 3rd gen mobile i7-3820QM and my backup laptop has i5-3610ME and I remember some people saying that Ivy Bridge processors cannot be undervolted. At the same time I see a lot of google search hits on undervolting Ivy Bridge cores so I am quite confused.

 

Is there any way to undervolt 3rd gen intel i5/i7?

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Yeah really sucks about Notebookreview forums shutting down. Someone was able to snag an archive of the forum though so you might be able to try searching it for any answers, not perfect though: https://www.nbrchive.net/

Desktop: i7 7700K @ 4.7Ghz, 16GB DDR4, Cooler Master H80i v2, 500GB M.2 SSD, Fractal Focus G *white* case, Gigabyte 1080 8GB

Laptop: EVGA SC17 1070: i7 6820HK, GTX 1070, 32GB DDR4, 256GB SSD, 1TB HDD, 4K Gysnc panel

Laptop: Eluktronics Mech 15 G2, i7 8750H, 1060 6GB, 16GB DDR4, 480GB Nvme SSD, 144hz panel  

 

 

 

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@SJLPHI

Intel added the integrated voltage regulator (FIVR) starting with their 4th Gen Haswell CPUs. 

 

Undervolting is not possible with 3rd Gen mobile CPUs. 

 

That is a definitive answer from someone that has been knee deep in Intel datasheets for the last 10+ years.

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Okay, does that apply to the K versions and desktop CPUs? A lot of people wrote online as long as Google finds they seem to be able to over/under clock and over/undervolt.

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5 hours ago, SJLPHI said:

does that apply to the K versions and desktop CPUs

Desktop CPUs handle the voltage separately from the CPU. On a 2nd or 3rd Gen desktop computer, you can set the voltage if the motherboard BIOS includes that feature. As far as I know, there were no laptops released during that time that had an adjustable voltage feature. 

 

That changed starting with 4th Gen. Even if the BIOS did not have an adjustable voltage feature, you could use Intel XTU or ThrottleStop to adjust the voltage. These programs can send voltage requests to the FIVR in the 4th Gen and up processors. Many desktop motherboards still have an option available in the BIOS so they can bypass the FIVR voltage regulator and supply voltage to the CPU directly. 

 

Underclock is supported by all CPU generations. When you underclock a 3rd Gen mobile CPU, the voltage will also decrease. This might have some people convinced that they are able to undervolt the CPU but really they are not. They are just slowing the CPU down. When FIVR is supported, you can change only the voltage without changing the CPU speed. 

 

The older Core 2 Duo technology allowed software controlled undervolting. The 1st, 2nd and 3rd Generation Core i CPUs do not support software controlled undervolting. That is why when you run ThrottleStop on a 3rd Gen Core i CPU, the FIVR button will not appear. It will be replaced with a TRL button instead. You can only change the turbo ratios of 3rd Gen CPUs. The FIVR did not yet exist so software cannot be used to change the voltage.  

 

Here is a paper about the FIVR, first introduced on Intel's 4th Gen Core i CPUs.

https://xdevs.com/doc/_PC_HW/Intel_FIVR_burton2014.pdf

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