# lm sensors - What is Tdie and Tctl?

## dman777

I have a AMD Ryzen 5 2600 6 core which I am enjoying very much with Gentoo. 

I am also using a ASrock motherboard. 

For lm sensors, I  have:

```

k10temp-pci-00c3

Adapter: PCI adapter

Tdie:         +34.0°C  (high = +70.0°C)

Tctl:         +34.0°C  

```

What is Tdie and Tctl? Which would I use for my  conky display?

----------

## Fitzcarraldo

Tdie is the temperature of the die of the CPU.

Tctl = Tdie + Tctl_offset on some CPUs, and is intended for fan control. See the section 'Temperature Reporting' in the following AMD blog post:

https://community.amd.com/community/gaming/blog/2017/03/13/amd-ryzen-community-update

See also https://www.hwinfo.com/forum/Thread-CPU-temp-sensors-explanation?pid=20914#pid20914

 *Martin, HWiNFO Author wrote:*   

> -CPU (Tctl): This is the T_control temperature available on AMD CPUs only. On several generations before Zen (Ryzen), this is not a reliable representation of the temperature. On AMD Zen series this is the temperature used to control cooling and is a fixed offset from the real CPU temperature. Offset is used mostly on X-series and some Threadripper CPUs; in such case two values are shown: Tctl and Tdie. If no offset is used, then only a single value is shown as Tctl/Tdie, which equals the real temperature.
> 
> -CPU (Tdie): This value is shown in case the CPU uses an offset from Tctl and represents the real temperature (Tdie = Tctl - Tctl_offset).

 

So you can display Tdie in Conky if you want to know the true temperature of the CPU.

----------

