AMD FX temps

[madcratebuilder]

You see all kinds of different temps reported as maximum for the FX8xxx or FX9xxx. I recently found a email from Alex Cromwell, he's the Senior Technology Director for Advanced Micro Devices.

SPECS :

Tcase (aka core temps) = MAX 61.1°C
***This temp is correctly reported in AMD Overdrive***
***This temp is correctly reported in HWMonitor under AMD FX-8350 > Temperature > Package***

Tjunction (aka socket temp) = MAX 70°C
***This is what is reported in the BIOS according to AMD***
***This temp is correctly reported in HWMonitor under Temperatures > CPU***

The maximum temperature for the FX-8350 CPU is 61.1C at Tcase. This is different from Tjunction (which the BIOS and programs like HWMonitor will report), and can easily be referenced through AMD OverDrive, or closely referenced through programs like CoreTemp/RealTemp. HWMonitor and BIOS software will report the Tjunction temperature which can be as much as 10C different from the Tcase temperature.

QUESTION :

1- Should I just disregard completely Tjunction temp and just focus on keeping Tcase temp within specs?
2- In the included pic I marked what I understand is Tcase, am I right?

Thank you for your time.

ANSWER :

Tjunction shouldn't be ignored specifically, as a Tjunction temperature that is in the 70s is definitely cause for concern, even if the CPU is only in the 40s, as that could indicate a hardware fault in the socket that could start damaging hardware. The 61.1C limit is for Tcase, but Tjunction is good to ensure that there isn't any damage to the NB controller, socket, or memory controller. It's just less important than Tcase for actual CPU temperatures, but is a good warning sign for issues with the board or northbridge.

Concerning your question regarding the temperatures with your processor. (1090) the maximum temperature threshold is 62 Celsius which set for the internal die (core) temperature of the chip. The core temperatures have an equational offset to determine temperature which equalizes at about 45 Celsius thus giving you more accurate readings at peak temperatures. The hindrance in this is the sub ambient idle temperature readings you speak of.

The silicon and adhesives used in manufacturing these processors has a peak temperature rating of 97+ Celsius before any form of degradation will take place. The processor also has a thermal shut off safe guard in place that shuts the processor down at 90 Celsius.

The Cpu temperature is read form a sensor embedded within the socket of your motherboard causing about a 7-10 Celsius variance form the actual Cpu temperature, which may be what you are reading about on the net.
I hope I was able to answer your questions, If you have any more inquiries don't hesitate to contact us.

You can use an application called AMD overdrive, that will allow you to monitor your temperatures accurately.

As long as your core temperature has not exceeded the high side of the 60 degree mark for extended periods of time you should be ok. 62 degrees holds a generous safety net to begin with.


Thank You

Alex Cromwell
Senior Technology Director
Advanced Micro Devices

Now you just need to determine what temp is Tcase and what temp is TJunction. Tcase is also called Core or Package. TJunction is also called Socket.

Tcase is usually about 8-10C lower than TJunction. Tcase at idle well show below ambient. Tcase uses a algorithm to determine the Tcase/Core/Package temp and it does not show accurate results until the chip is well above 30C and some chips even higher.

HWIno64 reports these needed temps, in my case with a Crosshair V Formula-Z motherboard I see the following.

CPU #0 AMD FX-9559
CPU 0=Tcase
CPU 0 Package=Tcase

ITE IT8721F (on board chip found on most asus boards, similar # on other boards)
CPU=TJunction
Motherboard=embedded MB sensor

ASUS boards may also have temps listed under-

ASUS ROG
T0=CPU/TJunction
T1=Southbridge
T2=Northbridge
T3=Motherboard

Desired temps
Tcase under 61.1C
TJunction under 70C

You can exceed these for short periods of time, you may encounter voltage throttling and high vrm temps. It may decrease the cpu's lifespan, IDK, I've been over these temps without anything bursting into flames. The CPU shuts down at 90C.

 

[madcratebuilder]

Tcase is usually about 8-10C lower than TJunction.

I'm adding that the above is normal when digi+ power setting are at or near default. Raising digi setting generates more heat across the board and result in higher "Tcase' or "core" temps that can meet or exceed "TJunction" or "socket" temp.