CPU Core Temperature Measuring - Facts & Fictions

Could someone explain the difference between the max Temperature of CPU (Tctl/Tdie) 64° and CPU CCD1(Tdie) 75° to me? I didn't notice such a big difference in temperature before. Before i took the screenshot the difference was even 15°. Is that "normal" ?
Also shouldn't at least one of the Cores (CCD1) then have that 75° as maximum? Or is that a different value?
 

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The AMD CPU/APU has dozens of temperature sensors across the entire CPU package and deriving a single temperature from all these values depends on how the calculation is done - which exact sensors are taken into account and if the final result is a maximum among them or an average value. When an average is calculated, it can be averaged during a specific interval and sampling of different intervals during highly fluctuating temperatures can also result in a large difference.
Unfortunately AMD doesn't disclose in detail how this calculation is done.
 
Tj,max (or better the Thermal Limit) might not always be constant and the thermal limit might change on some CPUs/APUs during runtime.
The "CPU Die (average)" value is what the CPU should be internally comparing against the actual limit and the "Thermal Limit" percentage shown in HWiNFO determines how close the CPU currently is to the limit.
 
Hello, I have one general question, and one specific one. (I understand it may not be possible to provide good answers, especially for specific question. No worries.)

1. General. Although the first few posts are highly informative and useful, they are around 9 or 10 years ago. Do you know if the inaccuracy variations are still similar or has it improved? (The same as first post but for 2022).

2. Specific. I run an OCed i9-9900ks at 5.1GHz which I managed to stabalize. Using Hwinfo 64vs 7.30. So I use CPU package, as if memory serves, that is the best one for core temps. Still correct on Intel?

Additionally I have customized my lay out and under, CPU Package, I have CPU IA Cores. They are very consistent in what they report as written below.

At idle IA core is 1 c degree cooler, but when running hot they are both the same. Today idle temps are 33c package, 32c IA cores.) Not so important, but at higher temps anything over 70 approx they match exactly almost 100% of the time. I think I know the answer but I am no expert and don't want to make this post too long. (Also I tend to get things wrong, ahem.)

So, I am asking Martin or any other person who knows well what your thoughts, or better facts about these two temps. I am wondering if it's the same sensor being used (AsRock z390 Phantom gaming 9, with Intel i9 9900ks) with one of them direct from the CPU and the other via Motherboard? See, that's probably silly or obvious to you guys, but I am curious and not really sure. Hence not writing out my whole likely flawed idea.

I'll leave it at that, it's not a big deal because as mentioned when checking even moderate loads they are the same. It's more curiosity....., or is my mobo about to catch fire, or my CPU explode? Just a slight exaggeration there to clarify my question.

Thanks to anyone who replies.

Also want to say I love HWinfo and have been using it for well over 10 years now. Great software. With so many variables between manufacturers etc it's quite something that that so much information is provided. Great stuff!!
 
The accuracy has improved over time and is much more uniform across the entire range. Initially the DTS was designed to ensure throttling occurs at the right time (temperature), so accuracy in the non-critical range wasn't important. But later when many tools started to report temperatures and and users paid a lot of attention, this was improved.
There are many sensors in the CPU located at various locations and there can also be a difference how the values are reported. Some sensors report the instant temperature which can fluctuate quite much under specific loads but sometimes it's more useful if the instant temperatures are averaged over a very short time interval. The "CPU Package" is such averaged value over last 256 ms.
 
Regardless the way each sensor is reported for Intel if I'm not mistaken (I own a Ryzen) Package temp is the edge temp of the die(?) IA cores temp is individual(?) core temp and GT cores temp is iGPU temp?
 
"Package" in Intel terminology means the entire CPU (entire package).
"CPU Package" temperature is defined as: "256 ms average of the hottest temperature of all Digital Thermal Sensors within the package calculated by the CPU".
 
Amazing stuff. I'd like to know how they construct a solid-state device that measures temperature. I'm familiar with boolean algebra and logic circuits, but I've never stumbled arcross the schematic for one of these DTS structures.
 
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