On a 4-core (4 physical, 8 logical cores), 3.5 Ghz box, MariaDB 10.3.4 consumes typically 35-40% of available CPU even when completely idle according to Task Manager. Please see image.

I cannot tell if previous 10.3 versions also did, as I don't have 10.3 running constantly in the backgorund. I just observed this now. This does not happen with MariaDB 10.1, MariaDB 10.2, MySQL 5.6, MySQL 5.7 and MySQL 8.0 (all those I have starting with Windows on this box), where the CPU-load is neglible unless the server is "doing real work".

As a result, the CPU clock frequency is always highest possible 3.5 Ghz (this CPU model is a 4th generation Intel with the option to scale down CPU frequency to around 40-50% of max. when there is no need for more) when MariaDB 10.3.4 is running.

-- Peter

-- Webyog