AMD: Ryzen Temperature Reporting is Wrong

Since the release of AMD’s Ryzen processors, some users have reported recording abnormally high temperatures from the 1700X and 1800X versions of the chip. Now, AMD has spoken about the issue, revealing that it set a 20oC temperature offset on the temperature reporting sensor of the two CPUs, in order to ensure “a consistent fan policy.” The company assures owners that new temperature monitoring software will compensate for the issue.

“The primary temperature reporting sensor of the AMD Ryzen™ processor is a sensor called “T Control,” or tCTL for short,” AMD’s Community Update for 13^th March reads. “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.”

“Specifically, the AMD Ryzen™ 7 1700X and 1800X carry a +20°C offset between the tCTL° (reported) temperature and the actual Tj° temperature,” the post adds. “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.”

“The table below serves as an example of how the tCTL sensor can be interpreted in a hypothetical scenario where a Ryzen processor is operating at 38°C,” AMD explains.