It helps while you take a break
With the recommended setting your PC only starts helping after you have not touched mouse or keyboard for 2 minutes.
When you sit down again, it stops after the current step and frees the graphics card and memory.
A PC usually has room to spare
Browsing, writing or watching videos, a PC mostly uses only a small part of its power.
Only this free part is shared, and you set how much of it yourself.
When you play, the game comes first
If you need the full power of the graphics card, for a game say, click “Pause” or “Stopp”. It takes effect at once.
With the recommendation it stops anyway as soon as you sit at your PC.
Too much? Just turn it back
If you give more of your own accord and notice something stuttering or slowing down, turn it back under “Rechenkraft teilen” (share computing) or pause.
Nothing of it is final, you can change it any time.