Synology docker HA low cpu usage

Hello,
I’m new in HA.
My problem is with history module in HA.
I host HA on synology ds 920+
My config folder is on 2 hdd (SHR mirror).
home-assistant_v2.db - 3.3GB.

When I try create one day history it tok few minutes… But my CPU usage keeps below ~5%…
How to speed it up ?