Thermal management for Intel 6th/7th Generation (Tcase vs. Tjunction)

[HLee]

Hi sir,

We have questions about Intel's sixth/seventh/eighth generation thermal management.

Data sheet volume from the Intel 6th Generation Intel Core processor family. 1, the thermal management section 5 (page 81) mentioned that in order to maintain the reliability of the processor, the processor must remain within the minimum and maximum Tj specifications. But on the intel website, Package Specifications is actually labeled Tcase. So is thermal design based on Tj or Tc?

However, between the 7th and 8th generations, the datasheet specifies the maximum thermal temperature design remains at the maximum case temperature (Tcmax) specification, but Tj is specified in the official website. which is right(Tc or Tj)?

I7-6700, Tcase = 71°C@

https://ark.intel.com/products/88196/Intel-Core-i7-6700-Processor-8M-Cache-up-to-4_00-GHz https://ark.intel.com/products/88196/Intel-Core-i7-6700-Processor-8M-Cache-up-to-4_00-GHz

Package Specifications

• Sockets Supported FCLGA1151
• Max CPU Configuration 1
• Thermal Solution Specification PCG 2015C (65W)
• TCASE 71°C

i7-7700T, Tjunction = 80°C

https://ark.intel.com/products/97122/Intel-Core-i7-7700T-Processor-8M-Cache-up-to-3_80-GHz?q=I7-7700T https://ark.intel.com/products/97122/Intel-Core-i7-7700T-Processor-8M-Cache-up-to-3_80-GHz?q=I7-7700T

Package Specifications

• Sockets Supported FCLGA1151
• Max CPU Configuration 1
• Thermal Solution Specification PCG 2015A (35W)
• TJUNCTION 80°C

i7-8700T, Tjunction = 100°C

https://ark.intel.com/products/129948/Intel-Core-i7-8700T-Processor-12M-Cache-up-to-4_00-GHz https://ark.intel.com/products/129948/Intel-Core-i7-8700T-Processor-12M-Cache-up-to-4_00-GHz

Package Specifications

• Sockets Supported FCLGA1151
• Max CPU Configuration 1
• Thermal Solution Specification PCG 2015A (35W)
• TJUNCTION 100°C

[idata]

Hello ddi,

I understand that you would like to know the reason why some processors show Tjunction and others Tcase. Answering your question, both are right. The difference here is that Tcase is for desktop processors while the Tjunction is for mobile processors. This is because the mobile processors do not have an integrated heat spreader. You can find more information in the link below: https://www.intel.com/content/www/us/en/support/articles/000005597/processors.html https://www.intel.com/content/www/us/en/support/articles/000005597/processors.htmlI hope the information provided helps.Regards,David V

[HLee]

Hi David,

Thanks for your reply. We want to know why Keby lake and coffee lake on the official website only indicate that Tjunction does not have Tcase temperature? Can it help confirm this problem.

[idata]

Hello ddi,

Thank you for your response.In response to your question, starting with the 7th generation Intel started adding only the Tjunction in the ark of each of the processors as you were able to see. This is because if the Tcase is needed you can always find it in the data sheet of the specific processor. Both measurements are there and if needed you can always check the different data sheet. Here is the one for the 7th generation:https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-gen-core-family-desktop-s-processor-lines-datasheet-vol-1.pdf https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/7th-gen-core-family-desktop-s-processor-lines-datasheet-vol-1.pdfHere is the one for the 8th generation:https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/8th-gen-processor-family-s-platform-datasheet-vol-1.pdf https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/8th-gen-processor-family-s-platform-datasheet-vol-1.pdfI hope this helps.Regards,David V

[HLee]

Hi David,

We have a question regarding the Thermal management on Intel 6th /7th Generation (Skylake/Kabylake) vs. 4th Generation (Haswell):

From Intel 4th Generation Haswell datasheet document Vol. 1, the Thermal Management section 5 (page 65) mentions that in order to retain the reliability of the processor, the processor must remain within the minimum and maximum Tcase specifications.

From Intel 6th Generation Skylake datasheet document Vol. 1, the TCC activates when reaches TjMax in page 85 and also mentions to consider temperature below the maximum allowed Tjunction and at the maximum TDP. So it is allowed to pass Tcase but within the Tjunction max limits?

It seems there's a change in the Thermal design considerations for new generation CPU? Can you confirm this?

[idata]

Hello ddi,

Thank you for your response.To answer your question, the thermal design conditions has not changed. You need to keep the processor working below the Tjunction/Tcase/Tjmax, if not then the processor will start closing applications and even eventually shut down to avoid any damage. It has been the same as before, always keep the processor under the measurements mentioned above in order to avoid damage and/or the abnormal shutdown of applications or the system itself. You can always check this information in the different data sheet of the processors. I hope this helps.Regards,David V

[idata]

Hello ddi,

I am following up with your case and see that we have not heard back from you.If you need more assistance do not hesitate to reply.Regards,David V