Please try the following measures to lower the CPU load.
1. Increase the Audio Buffer size as much as possible within the range of not too much affecting the audio latency.
2. Be sure to select "Medium speed" for waveform drawing rate from Preferences > View > Waveform.
If you select "Low speed", the CPU power will be adversely increased because OpenGL is not used.
3. If you do not use Sampler, close the panel. When using the Sampler panel, unload from unnecessary slots.