Preview && Export GPU nVIDIA vs AMD

Hello, I am using an nVIDIA 4080 Super, under Preview & Export i see the GPU defaults to AMD and when I change it to nVIDIA i see no significant performance enhancement, I need to understand why this setting is even there and what is its function?

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That’s just for encoding to H264/H265. If you change the AI processor in Preferences, that might make more of a difference.
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