If you are currently putting together a Ryzen 7 1800x or 1700x build and are planning your cooling solution based on current reported temperatures from reviews, then you may want to read this before spending a fortune on cooling or chasing down temperature issues. It seems that AMD has incorporated a +20°C temperature offset with these two CPUs and unfortunately didn’t make that very clear to reviewers. As a result, you may be seeing very inaccurate readings.
This +20°C temperature offset means that most software will be displaying the offset reading, rather than the actual junction temperature. As a result, AMD is advising that users subtract 20°C from their reported Ryzen 7 1800x and 1700x values to get an accurate reading on the junction temperature.
The reason for this offset in temperature is due to Ryzen’s use of a tCTL sensor which is derived from the junction (Tj) temperature—the interface point between the die and heatspreader. It is offset on certain models to ensure all Ryzen 7 CPUs have the same maximum tCTL value and a consistent fan control policy across all three processors.
We have since updated both our Ryzen 7 1800x and 1700x reviews with this information underneath the temperature graphs. Interestingly enough, AMD chose to fix this in Ryzen 7 1700, so those of you buying that CPU will not need to take this offset into account.
According to AMD’s statement on the matter, the company is hoping that software will eventually be updated to recognise the temperature offset and start displaying the actual junction temperature.
KitGuru Says: This really seems like the sort of thing that should have been in the reviewer’s guide to avoid confusion before launch. If you are planning a Ryzen build right now, make sure you take this offset into account when planning on your cooling solution etc.