gpu usage drops after a time

[emirsenkul]

gpu usage drops after a time in rainbow6siege game (and others) my gpu usage starts %98-99 when i started the computer but after playing/or idling doesnt matter) it drops to %60 percent and my fps drops a lot when i restart the computer its getting fixed why is that?
its not overheating 60-65 celcius its not bottlenecking either
specs:
i7 8700k
1080ti

 

[emirsenkul]

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