Right after Windows core parking bug has been reported, AMD's Robert Hallock (previously the Head of Global Technical Marketing for AMD) has posted a few more details explaining certain behaviour of Ryzen. In his blog post, Robert talks about the temperature reporting offset which was new to us.


According to AMD, the two flagship models features a so called “Temperature Reporting Offset” in order to keep a "consistent fan policy". In other words AMD is forcing the internal temperature sensors to report temperatures to software with a 20°C offset. The primary sensor on the AMD Ryzen CPU is called "T Control" or tCTL - in short. All the CPU models on AM4 motherboards have the same maximum tCTL value. The tCTL sensor is derived from the junction temperature (Tj) but on a few models there is a certain offset. This approach keeps a "consistent fan policy" on all AMD Ryzen CPUs.

More in detail, the AMD Ryzen 7 1700X and 1800X have a +20°C offset between the tCTL temperature and the real Tj temperature. Basically the temperature these CPUs report to the software is 20°C above the actual core temperature. The Ryzen 7 1700 is not affected from this and AMD is mentioning that monitoring software will soon adapt to automatically consider the tCTL offset. If for example your system is equipped with an AMD Ryzen 7 1800X processor and a True Junction temperature of 38°C is the case 58°C are going to reported due to the 20°C (tCTL) offset.




Source: AMD