Junction Temperature Max missing in product spec for Xeon Gold 6226R Processor

[sathyarao]

Hi Intel, I only see a Case Temperature in product specification of Xeon Gold 6226R Processor which is 85°C. We are reading temperatures from `/sys/class/thermal/thermal_zone/temp` and at times the value is reaching close to 85°C. I found that this reading refers to Junction Temperature and not Case Temperature. Is that correct? If yes could you help getting Max Junction Temperature rating for this processor? Thanks

[n_scott_pearson · Accepted solution]

The Maximum Junction Temperature (Tjmax) can vary from one individual processor to another, but is typically in the vicinity of 100c. It can be programmatically obtained by reading the IA32 Temperature Target MSR.

Hope this helps,

...S

[sathyarao]

Thanks @n_scott_pearson.

I ran 'sudo rdmsr 0x01A2' which yielded: 660a00, which means Tjmax=102°C, if I'm reading it correctly.

However I don't see information about Tjmax or IA32 Temperature Target MSR in the datasheet of my processor:  Xeon Gold Scalable 6226R Processor. 

Could you help me point to documents where I can find more information about Tjmax / IA32 Temperature Target MSR?

Thanks

[n_scott_pearson]

Well, that's because there's no specific Tjmax value that they could list - and, as it detailed in section 2.1.6 of volume 2 of the datasheet, MSRs are separately documented in the Intel 64 and IA32 Software Developer's Manuals.

...S

[sathyarao]

Thanks @n_scott_pearson. Much appreciated!