Unknown TJunction Location on Intel Core i9-13900K processor.

[kodo]

At what location in the Intel Core i9-13900K Processor, is the TJunction temperature recorded?   

My many reworded queries, have always returned, that Intel's stock TJunction maximum is spec'd at 100 °C.   But never, has a location other than, at "the junction", been returned.   What does Intel's use of this name/word "junction", refer to?   Precisely what temperature(s) is/are recorded, then listed as the TJunction of the processor, in Intel's Processor Specifications?   

[No proprietary info is asked for, or need be given.]

[n_scott_pearson · Accepted solution]

It is the Maximum Junction Temperature (Tjmax) that is the important factor. While it is talked about as being 100c, in Desktop this threshold can vary from one individual processor to another. During the silicon validation process, the individual processor's Tjmax temperature is determined and its offset from 100c is burned into a set of fuses in the processor. Based upon the settings of these fuses, a Model-Specific Register (MSR) exposes an absolute temperature value for the processor's Tjmax temperature.

The DTS (Digital Thermal Sensors) in the processor actually measure the distance, in an approximation of Celsius degrees, that the current temperature of a particular (hotspot) location in the processor is below the Tjmax temperature. Readable DTS are available for each of the processor's Cores and for the GPU. Other DTS, in proprietary locations, along with the Core and GPU DTS, are used to determine (via proprietary algorithm) an overall Package temperature for the processor.

The CPU Cores, GPU and Package temperatures are exposed in MSRs as well. To determine the absolute value for any particular DTS, you take the Tjmax value from the one MSR and subtract the current offset value from the MSR for that particular DTS. Software can utilize a device driver to read the MSRs and present readings. Software applications - AIDA64, HWiNFO64, CPU-Z, GPU-Z, CoreTemp, etc. - all present some or all of these sensor readings. The Windows O/S also presents some of these temperature readings in its Task Manager application.

For more information, consult these sources:

• Information about Temperature for Intel® Processors
• What is the Maximum Temperature of My Intel® Processor?
• Tom's Hardware's Intel CPU Temperature Guide 2023
• PC World's How to check your PC’s CPU temperature

For information on the MSRs and how to read them, consult the Intel® 64 and IA-32 Architectures Software Developer Manuals.

Hope this helps,

...S