Good question. I haven't heard any future plans. My understanding is that TB3 reserved some of the throughput (for video, even if unused?), and then the remain

Good question. I haven't heard any future plans. My understanding is that TB3 reserved some of the throughput (for video, even if unused?), and then the remaining throughput went through 8b/10b encoding, which left ~26Gbps as the maximum theoretical PCIe bandwidth (significantly less (-18%) than the PCIe 3.0 x4 connection's 32Gbps). I don't know if there's still restrictions that prevent PCIe from making more use of the link in USB4/TB4. That seemed like a weird restriction, and it'd be especially weird not to see such a big gap when there is USB4 80Gbps. Anyhow, the encoding at least has gone from 8b/10b (+25% overhead) to 64b/66b or 128b/132b (+3%), which I believe should boost TB4 numbers a little. In practice, rather than the 26Gbps of PCIe it seems like we might be able to get, I've found similar-ish reports that a bit over 22Gbps was all TB3 could typically manage when doing a drive test... I don't know but I'd be very curious to get more details on where the missing 4Gbps are. How much do we lose to NVMe overhead, how much is lost to tunneling overhead, what other factors are there? I haven't heard any real data about what if any additional latency there is. One test I'd like to see is what happens to drive-speed as we go from direct attached, to 1 hub, to 2 to 3 hubs. As for the future, lots of good questions there; I haven't stumbled into any juicy tidbits at this time. A simple boost to PCIe 4.0 is all too likely, but how great it'd be to specify something more general/generic. It'd be great to see tunnels that have either more fan-in or more fan-out than the underlying connection: here's 8 different PCIe 6 x1 devices plugged in, and yes they're oversubscribed but they all work fine, that'd be a lovely example to see. But that's probably pretty pie in the sky right now.