Re:Van Gogh, AMD’s Steam Deck APU
by vetinari on Monday March 06, 2023 @07:33AM
(#35040238)
With USB4 the PCIe tunneling is optional; with TB it is mandatory.
[ Parent
| on HN ]
Ehm, the specification is clear that all external ports should expose PCIe tunneling? Or is there something that changed?
I don't know what Microsoft based their claim about it (maybe their own requirements in Windows HCP?)
From the spec:
2.1.1.5 USB4 Host
Host contains:
* A Host Router.
* A USB 2.0 Host.
* An Enhanced SuperSpeed Host.
* A DisplayPort Source.
Host can also optionally contain a PCIe controller or PCIe switch.
A USB4 Host supports 20G USB4 operation (Gen 2). It optionally supports 40G USB4 operation (Gen 3) and 80G USB4 operation (Gen 4).
Hmm, you're right - it's Windows HCP. I found a random statement when they mandate tunneling support to "Maximize compatibility across ecosystem".