AMDZENTEMP(4) | Device Drivers Manual (x86) | AMDZENTEMP(4) |
amdzentemp
— AMD
Zen CPU family on-die digital thermal sensor
amdzentemp* at amdsmnbus?
The amdzentemp
driver provides support for
the on-die digital thermal sensor present on AMD Ryzen CPUs and some later
AMD Opteron CPUs.
These sensors provide 0.125°C accuracy. There is one sensor for each CPU socket.
The amdzentemp
driver reports temperatures
through the envsys(4)
API.
Sensor | Units | Typical Use |
CPUN sensor0 | μK | cpuN temperature |
The amdzentemp
driver first appeared in
OpenBSD 4.4 named “kate”. It was then
ported to NetBSD 5.0 under the name
amdtemp(4). The
FreeBSD version of the driver was updated with
support for newer AMD CPUs. For NetBSD, the support
for the newer CPUs was separated into its own
amdzentemp
driver.
The amdzentemp
driver was written by
Constantine A. Murenin
<cnst@openbsd.org>
whilst at the University of Waterloo. Porting of support for the newer AMD
CPUs from FreeBSD was provided by
Ian Clark.
The temperature reading provided to envsys(4) needs to have a CPU-dependent offset applied. For Ryzen X processors, the offset is 20°C, while for Threadripper processors an offset of 27°C is needed.
The sensor has a thermal-trip value which should be retrieved and provided to envsys(4) as the sensors critical-maximum value.
April 20, 2020 | NetBSD 10.99 |