QSV顯卡使用率約50%卻掉影像fps - 實況

我的cpu是i7-7700 (intel-630)
顯卡是GTX-1070
作業系統是win10 64bit

OBS設定QSV，上傳5500kbps(CBR) 到twitch
用途balanced，設定檔High
解析度1920x1080 @60fps

我發現OBS常常出現掉禎的情形
但是掉禎的當下intel-630使用率僅50%上下(工作管理員)

請問一下這是怎麼樣的原因呢？

感謝大家的解答!

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"Volodya, my child, I know that it is for our motherland...
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