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apo11o But as general background info, the way USB-C works (prior to USB4, which this display doesn't support) is that it has 4 high speed lanes. Each lane can be allocated to video or USB 3.x data (or Thunderbolt, but that isn't relevant here). A full DisplayPort interface requires 4 lanes. Running USB 3.x data requires 2 lanes, which means that if you want to run video and USB 3.x together, your video bandwidth gets cut in half. USB 2.0 flows over pins dedicated to that purpose within the USB-C connector.
When you select High Data Speed, the connection is configured to support 2 lanes of DisplayPort and 2 lanes for USB 3.x. High Resolution causes the display to set up the connection for 4 lanes of DisplayPort and USB 2.0 (using those dedicated pins). The M1 Mac Mini supports DisplayPort 1.4/HBR3 over USB-C. Half of a DP 1.4 interface is enough for 4K 60 Hz, but apparently not 4K 60 Hz HDR. Limiting your USB speeds to 2.0 frees up more bandwidth, which is apparently needed for HDR. If you had a system that only supported DisplayPort 1.2/HBR2 over USB-C, this option is even more important because in that case you have to run High Resolution even to get 4K 60 Hz, otherwise you'd be limited to 4K 30 Hz if you wanted USB 3.x. This setting also comes into play on QHD/1440p displays where when you have a DP 1.2 system, you can choose to have QHD 60 Hz plus USB 3.x or dual QHD 60 Hz (via daisy chaining) with USB 2.0. But macOS doesn't support DisplayPort daisy chaining.
dell 论坛搜到的，好像 8 位和 10 位就差了 hdr 部分，感觉 hdr 平时真用不到，这个显示器的 hdr400 没啥用