topic Re: DTS / Tcase Gradient? in Mobile and Desktop Processors

DTS / Tcase Gradient?

CCapt — Sun, 11 Dec 2016 22:45:20 GMT

What is the thermal gradient or difference in degrees centigrade between DTS (Digital Thermal Sensor) and Tcase (laboratory embedded IHS thermocouple described in datasheets) at 100% TDP for the following desktop processors?

Die / IHS TIM:

i7 6700K

i7 4790K

i7 4770K

i7 3770K

Die / IHS Solder:

i7 2700K

i7 880

Q9650

Q6700

Although the server datasheets are more detailed, both the desktop and sever datasheets leave much to interpretation. Any further information would be helpful.

Thanks,

Re: DTS / Tcase Gradient?

idata — Mon, 12 Dec 2016 22:10:31 GMT

Hello CompuTronix:

In regard to your inquiry, we will start an investigation and a research in order to try to gather the information you are requesting.

As soon as I get any updates I will post all the details on this thread.

Any questions, please let me know.

Alberto

Re: DTS / Tcase Gradient?

idata — Thu, 22 Dec 2016 01:00:18 GMT

Hello CompuTronix:

I just wanted to let you know that I just received the results of our investigation and here are the details:

Digital Thermal Sensor (DTS): Each processor has multiple on-die Digital Thermal Sensors (DTS) which report instantaneous temperature that is relative to a fixed temperature (Tjunction Max). The primary function of the DTS is to regulate thermal protection mechanisms.

Tcase: is the appropriate case temperature that is defined by the applicable thermal profile. For example Tcase values are listed w.r.t power for a thermal profile. Tcase is measured at the geometric center of the package

Hence the datasheet doesn't list the thermal gradient between DTS and Tcase.

Please let me know if you need further details on this matter.

Any questions, please let me know.

Alberto

Re: DTS / Tcase Gradient?

CCapt — Sat, 24 Dec 2016 00:54:38 GMT

Alberto,

Thank you for the reply, however that doesn't answer my question.

Respectfully, it's common knowledge that everyone monitors Core (DTS) temperatures, which I'm sure was not Intel's original intention, but that's the reality of the situation. Tcase specifications are based on a combination of processor TDP and its stock cooler TDP. Since Tcase is a factory only measurement, it can't be monitored by the end user, which is obviously why everyone monitors Core temperatures.

However, we know that DTS and Tcase are relative to one another, and their temperatures rise and fall together, where DTS temperatures are approximately 5C higher than the temperature at the laboratory IHS imbedded thermocouple (Tcase) at 100% TDP. Thus the term "gradient". We also know that a tighter gradient indicates better heat transfer from the Die to the IHS.

Further, many websites which review Intel processors such as tomshardware.com, where I'm a moderator and author, know that the gradient increased when Intel changed from Indium solder to Dow Corning TIM on Desktop processors beginning with Core i 3rd Generation Ivy Bridge. Research from other enthusiast websites suggest that the gradient on 3rd through 6th Generation desktop processors may be as high as 7C.

I've been actively engaged in the topic of Intel processor temperatures for over 9 years, and have read all the datasheets from 65 to 14 nanometer, as well as assorted other white papers. Here's an older Intel document that discusses the DTS / IHS "gradient" which is shown in Figure 5 - http://arxiv.org/ftp/arxiv/papers/0709/0709.1861.pdf http://arxiv.org/ftp/arxiv/papers/0709/0709.1861.pdf

Similarly, I'm sure the relationship between DTS and Tcase has henceforth been well documented by your thermodynamics engineers for each processor variant. As a fellow engineer, rather than speculate, I'm asking for more recent information which is not available in the datasheets.

I await your reply.

Re: DTS / Tcase Gradient?

idata — Tue, 27 Dec 2016 00:12:36 GMT

Hello CompuTronix:

Thank you very much for providing that information.

In this case we will do further research and we will continue with the investigation in order to try to find more recent information about this subject with all the details you requested.

As soon as I get the any updates I will post all the information on this thread.

Thank you for your patience.

Any questions, please let me know.

Alberto

Re: DTS / Tcase Gradient?

CCapt — Wed, 28 Dec 2016 02:28:34 GMT

Alberto,

Thank you very much for your efforts. I'll be standing by.

Re: DTS / Tcase Gradient?

idata — Wed, 11 Jan 2017 17:10:49 GMT

Hello CompuTronix:

Let me apologize for any inconvenience.

I just wanted to let you know that I sent you a private message.

Regards

Alberto

Re: DTS / Tcase Gradient?

idata — Tue, 17 Jan 2017 22:38:21 GMT

Hello CompuTronix:

I just wanted to check if you received the private message and if you need further assistance with this matter?

Any questions, please let me know.

Regards

Alberto