No amount of something
Definition 1 of 1
Pro Tip 1/3Hopelessness Expressed
This phrase often conveys a sense of futility or hopelessness towards achieving something. 
No amount of studying seemed to help her pass the exam.
Pro Tip 2/3Fixed Outcome
It is used when the outcome is unlikely to change, regardless of effort or resources invested. 
No amount of persuasion could convince her to stay.
Pro Tip 3/3Emphasize Ineffectiveness
The phrase emphasizes the ineffectiveness of an action or resource in altering a situation. 
No amount of rain could save the withered crops.