我記得XBOX ONE是透過軟體模擬器來相容前代主機：360/初代XBOX，遊戲公司同意相容某遊戲後，微軟自己的模擬器針對個別遊戲調整細部畫面&速度（Ex. 忍者外傳2 on One X畫質速度強化4K60，忍者外傳3就沒有畫質強化但速度比360真主機更穩定）
"Supported Xbox 360 games will run within an emulator"
"Improved frame rate stability – The increased performance of the Xbox One allows titles to hit and maintain their max frame rate more consistently."
"Games utilizing a dynamic resolution will hit their max resolution more often, or at all times due to the increased performance of the Xbox One."
https://en.wikipedia.org/wiki/List_...es_for_Xbox_One
隨手翻了一下Wiki的文件引用相關說明。