AMD’s R7 1800X and 1700X report higher temperatures with a 20 degree offset

AMD's R7 1800X and 1700X report higher temperatures with a 20 degree offset

AMD’s R7 1800X and 1700X report higher temperatures with a 20 degree offset

 

AMD’s R7 1800X and 1700X report higher temperatures with a 20-degree offset, which means that only the R7 1700 is reporting the correct CPU temperatures at launch.   

In Ryzen CPUs AMD places their thermal sensor “T-Control/tCTL” at the interface point between the CPU and the heatspreader, sensing what is called the junction temperature (Tj). With the AMD R7 1700X and 1800X AMD uses a thermal offset of 20 degrees to force higher fan speeds on fan speed/thermal curves, making these CPUs list thermals that are hotter than they actually are.  

Below is a table which showcases these offsets, explaining why users of the R7 1700 are reporting much lower thermal results than the R7 1800X and 1700X, as these are reporting higher thermals.  
 

Product Name True Junction Temp (Example) tCTL Offset for Fan Policy Temp Reported by tCTL AMD Ryzen™ 7 1800X 38°C 20°C 58°C AMD Ryzen™ 7 1700X 38°C 20°C 58°C AMD Ryzen™ 7 1700 38°C 0°C 38°C

   

This explains why initial reviews for the 1800X reported that Ryzen could run at 80 degrees without their coolers getting hot to the touch, as their CPUs were, in reality, running at around 60 degrees with AMD’s Ryzen Master utility reporting higher thermals.  

In time, it is expected that software will be updated to better report Ryzen’s thermals and we hope that AMD will officially reveal more details on their CPU’s thermal limits soon. 

 

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