I have a r7 1700 but it is difficult to see correctly the frequencies in use 100%. With blender opendata maximum temperature 78C ° Cooler stock without oc.
Linux ubuntu 18.10 I am asking amd for a basic Linux driver at least for basic controls of real frequencies and temperatures.
This is a link on how to install a linux program to Overclock and monitor your Ryzen CPU/APUs: https://forum.level1techs.com/t/overclock-your-ryzen-cpu-from-linux/126025 . I don't understand it but you probably will. Even though it is used for Overclocking the Ryzen but I imagine you can use it also to monitor your Ryzen CPU.
From Github it has an updated version of CONKY for Ryzen CPUs; CPU Ryzen 1700 temperature monitoring lm_sensors &... - GitHub Community Forum
From LinuxConfig website on installing Ryzen Temperature monitoring: https://linuxconfig.org/monitor-amd-ryzen-temperatures-in-linux-with-latest-kernel-modules
I am not sure if these two programs can be configured to monitor ryzen frequencies or not.
If not try this very good Linux Forum called Phoronix: https://www.phoronix.com/forums/