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Definitions of sensors for classic Mac pro display

Control fans on Apple hardware: iMacs, Macbooks, etc

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wdhall
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Joined: 05 Oct 2015, 18:26

Definitions of sensors for classic Mac pro display

Post by wdhall »

All,

I'm looking for help in understanding the various sensors and their associated values in Macs Fan Control for my classic Mac Pro. Most are self explanatory but I don't know what the sensor labeled "CPU A core from PCECI" means especially the "PCECI" part. Similarly, what does "IOH Heatsink" mean and where is the sensor located? Also, I assume the "PCIE slot 1" is reading the on-board PCIE graphics card sensor through the PCI slot but I'm not positive. Lastly, I don't know what "PSU1 Secondary Component" means.

I encoded a Blu-Ray last night and set the speeds for EXHAUST, INTAKE and BOOSTA to limit the CPU A core from PCECI to a maximum temp. of 80 degrees Celsius but there may be a better way to ensure the CPU does not get close to the max. (attached screen shot)

Any insight is appreciated.
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wdhall
Posts: 5
Joined: 05 Oct 2015, 18:26

Re: Definitions of sensors for classic Mac pro display

Post by wdhall »

No input on these questions, even from Steven?

I now understand that "IOH Heatsink" is for the Northbridge chip but the PCECI is still puzzling. I read a post that indicated this was the difference between the current core temperature and the maximum temperature but that doesn't make sense as this number increases when the diode temperature rises.

Also still confused about what the "PSU Secondary Component" temperature.
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Steven
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Re: Definitions of sensors for classic Mac pro display

Post by Steven »

wdhall
Sorry.

All these sensors are undocumented. I plan to improve them in future updates with more meaningful names (or popup information)
http://forums.macrumors.com/threads/mp- ... s.1601231/

"CPU A core from PCECI" is how many degrees you are from the temperature you never want to reach (TJMax they call it). It is a countdown, so the higher the number, the better. Many apps assume TJMax to be 100C. And this is to do with cores, not diode.

Actually MFC already calculates TjMax - PCECI
wdhall
Posts: 5
Joined: 05 Oct 2015, 18:26

Re: Definitions of sensors for classic Mac pro display

Post by wdhall »

Steven,

Thanks for the reply. I read the MacForums post you linked but the explanation contained therein does not seem logical.

For example, if TJMax is 100C and CPU A Diode is 80C, then one would surmise that CPU A core from PCECI would be somewhere around 20C depending on where the two sensors are located. In my screenshot above if TJMax is 100C and CPU A Diode is 69C, CPU A core from PCECI should be more like 30C, not 79C. If the MacForums explanation is correct, that indicates TJMax is 140C.

In other words, there should always be an inverse relationship between CPU A Diode and CPU A core from PCECI if what is posted in MacForums is true.

Unfortunately I have found no other definition of the acronym "PCECI", that would probably answer my question.

Cheers.
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