1. Click the menu Management
2. Click the tab Settings
3. Click on the second row the tab Calculations
Here you can choose which calculations you want to stop (temporarily).
Equivalent of Complete Ancestor Generations (ECG)
Number of Ancestor Generations (NAG)
Calculated extra fields
4. Uncheck the boxes for the calculations you want to stop or uncheck Enable calculations to stop them all.
5. Click Save.