AMD has just issued a new community update on its brand new Ryzen CPUs, addressing issues over thread scheduling on Ryzen processors - but also detailed the problems over temperature reporting on Ryzen.
AMD explains in the post that the "primary temperature reporting sensor of the AMD Ryzen processor is a sensor called 'T Control,' or tCTL for short. The tCTL sensor is derived from the junction (Tj) temperature-the interface point between the die and heatspreader-but it may be offset on certain CPU models so that all models on the AM4 Platform have the same maximum tCTL value. This approach ensures that all AMD Ryzen processors have a consistent fan policy".
The post continues in detail, with AMD explaining: "Specifically, the AMD Ryzen 7 1700X and 1800X carry a +20°C offset between the tCTL° (reported) temperature and the actual Tj° temperature. In the short term, users of the AMD Ryzen 1700X and 1800X can simply subtract 20°C to determine the true junction temperature of their processor. No arithmetic is required for the Ryzen 7 1700. Long term, we expect temperature monitoring software to better understand our tCTL offsets to report the junction temperature automatically".
Some owners of Ryzen 7 1700X and 1800X processors are already adjusting for it, but personally - I don't think you should be having to adjust anything on your flash new CPU. AMD should be letting Ryzen report its absolute true reading of temperature, instead of a massive 20C offset.
But, is it such a bad thing?
Right now, I've got my AMD Ryzen 7 1800X processor in my ASUS Crosshair XI Hero motherboard, cooled by the Noctua NH-U12S SE-AM4 cooler (an air cooler, no watercooling here on Ryzen yet). My idle temperatures are 60C, but I'm doing some more testing now and will report back with the changes.
Another thing to remember is that this is a radically new CPU architecture for AMD, and these smaller bugs will be ironed out in due time - not as a "red shill", but it's the absolute truth. On top of that, we have the motherboard manufacturers not having enough time to tweak their boards - with all of this flowing into the market now, the fixes will be quick and swift.