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Comment by LoganDark | Hacker News Reader

I don't understand how a 10GbE adapter is possible without Thunderbolt, or why not being Thunderbolt makes it smaller. In my experience USB speeds faster than 3 don't happen in practice unless you have a Thunderbolt port and device. Maybe I just don't have devices that use the faster USB speeds, but Thunderbolt has always been the one and only way to exceed the speed of USB for me.

I think USB 4 exists based on the Thunderbolt spec (or the other way around?), but doesn't require any Thunderbolt capabilities and therefore isn't very telling.

I think Apple's approach of supporting Thunderbolt 4/5 on every USB port of the MacBook Pro is the only sustainable way forward.

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Because USB can do 2 lanes of 10 gbps. So that's 20gbps. 10 < 20. Thunderbolt isn't part of the equation here because it's not a thunderbolt device or thunderbolt host (even if the port is thunderbolt capable).

The reason it's smaller to go with USB is that AFAIK thunderbolt only bridges to other interfaces like USB or PCIe. So any thunderbolt NIC is actually thunderbolt -> PCIe, then PCIe -> Ethernet. USB is more often interfaced with directly. 2 big power hungry chips vs 1. 1 < 2 so it is smaller.

Thunderbolt also carries overhead vs oculink. Thunderbolt tunnels PCIe. The PCIe tunnels the ethernet traffic. Oculink is just PCIe, which is why it's not as hot pluggable but gets significant performance increases for PCIe devices. USB in this case tunnels Ethernet traffic. So thunderbolt NICs have 2 layers, USB has 1. 1 < 2. Less overhead means lower power and less heat so smaller heatsinks, fewer chips means smaller board so smaller device. If more devices had oculink connectors, it's highly conceivable that an oculink adapter would also be smaller than a thunderbolt NIC, because again there's no such thing as a thunderbolt NIC just a thunderbolt -> PCIe -> Ethernet.

> Thunderbolt isn't part of the equation here because it's not a thunderbolt device or thunderbolt host (even if the port is thunderbolt capable).

The article directly states this device is smaller than a Thunderbolt adapter. I was not calling Thunderbolt part of the equation, just asking how it's possible to reach high speeds without it.

The rest of your explanation makes sense, thanks.

Thunderbolt 4 and 5 are just USB (40, 80 Gbps) with mandatory support for otherwise optional USB-C features like video and high power.

Now that USB 4 is just Thunderbolt with less features, yes. Mostly by definition, though.

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