4 ms·

I've heard that Thunderbolt and USB4 "merged" -- does this mean it's Thunderbolt at the lowest layers and USB4 is encapsulated? Or are there two different signa

• wtallis 4y ago
  When USB is involved, you can always assume they chose the more complicated option. USB4 is a competing, incompatible method of encapsulating and multiplexing PCIe, DisplayPort and USB data packets over one cable. But the USB4 spec incorporates Thunderbolt as an alternate mode. Thunderbolt support is required for USB4 hubs but optional for USB4 hosts and devices. So you will often (maybe even always, in practice) be able to use a USB4 host port as a Thunderbolt port.
  • izacus 4y ago
    It's worth mentioning that Microsoft seems to demand support for Thunderbolt mode for Win11 certification.
• deleted 4y ago
  [deleted]
• rektide 4y ago
  Don't let Usb4 hear you saying that, it'll be mad. USB4 is usb4. Which... very closely resembles thunderbolt. Thunderbolt 4 is PCIe tunneling over USB4. Note also Display Port now works similarly: instead of switching to an alt-mode (dedicating half the lanes to a video signal), in USB4 Display Port packets are encapsulated in usb4 packets. So now you can attach a variety of displays, to a tree of hubs, provided you have bandwidth, whereas this was a cluster fuck for a while... it's part of the reason usb-c output hubs were so rare, no one wanted to explain to consumers why a couple monitors with usb-c cables wouldn't work with their hub. Now, they will (provided there's sufficient bandwidth).