AMDTEMP(4)

💖 AMDTEMP 💖

okay bestie, sit down, we're talking about amdtemp — the device driver for the AMD processor on-die digital thermal sensor. it's a kernel interfaces manual page, so it's giving very much "close to the metal" energy, but don't stress, i got you 🫶

---

✨ SYNOPSIS ✨

so there's two ways to get this driver living in your system, and both are lowkey iconic:

way one — compile it straight into the kernel. drop this line into your kernel configuration file:

device amdtemp

way two — load it as a module at boot time. put this in loader.conf(5):

amdtemp_load="YES"

pick your fighter, they both slay 💅

---

🌸 DESCRIPTION 🌸

the amdtemp driver provides support for the on-die digital thermal sensor present in AMD Family 0Fh, 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors. that's a LOT of families, she's versatile, she's booked and busy.

for Family 0Fh processors, the amdtemp driver reports each core's temperature through sysctl nodes, named:

dev.amdtemp.%d.core{0,1}.sensor{0,1}

and the driver ALSO creates dev.cpu.%d.temperature in the corresponding CPU device's sysctl tree, which displays the maximum temperature of the two sensors located in each CPU core. two sensors per core and she picks the hotter one, main character behavior honestly 😭

for Family 10h, 11h, 12h, 14h, 15h, 16h, and 17h processors, the driver reports each package's temperature through a sysctl node, named:

dev.amdtemp.%d.core0.sensor0

and yes, the driver also creates dev.cpu.%d.temperature in the corresponding CPU device's sysctl tree, displaying the temperature of the shared sensor located in each CPU package. one sensor, one package, no drama 🌈

---

🎀 SYSCTL VARIABLES 🎀

this one little variable is available as both a sysctl(8) variable and a loader(8) tunable, which is very generous of it:

• dev.amdtemp.%d.sensor_offset — add the given offset to the temperature of the sensor. default is 0. that's it, that's the whole vibe. tweak it if your readings need a lil nudge ✨

---

🦋 SEE ALSO 🦋

• loader(8)
• sysctl(8)

---

👑 HISTORY 👑

the amdtemp driver first appeared in FreeBSD 7.1. a legend, a pioneer, an icon 💖

---

🫶 AUTHORS 🫶

these three absolutely ate, no crumbs left:

• Rui Paulo <rpaulo@FreeBSD.org>
• Norikatsu Shigemura <nork@FreeBSD.org>
• Jung-uk Kim <jkim@FreeBSD.org>

---

⚠️ CAVEATS ⚠️

okay this part is important, bestie, read it twice, i'm serious 🙈

for Family 10h and later processors, this is the word-for-word tea from the BIOS and Kernel Developer's Guide (BKDG) for AMD Processors:

"(the reported temperature) is a non-physical temperature measured on an arbitrary scale and it does not represent an actual physical temperature like die or case temperature. Instead, it specifies the processor temperature relative to the point at which the system must supply the maximum cooling for the processor's specified maximum case temperature and maximum thermal power dissipation"

so like… the number is real, but it's not a physical temperature, it's a relative scale situation. don't go around telling people your die is at that exact temp, because it's literally not that. the source is the BKDG at http://developer.amd.com/resources/developer-guides-manuals/ — iykyk 💀

---

and that's the whole page, babes!! this came to you from the Debian crew, dated September 5, 2017, and it's the AMDTEMP(4) page — stay cool, literally, and go check your temps 💅✨🎀