<https://everything.explained.today/USB4/> Did you know it is USB4, not USB 4? But USB 2.0, not USB2? I now have two Macs that I want to connect via Thunderbolt 4. I don't know how to tell if a particular cable will work.
On Fri, Feb 28, 2025 at 03:23:07PM -0500, D. Hugh Redelmeier via talk wrote:
<https://everything.explained.today/USB4/>
Did you know it is USB4, not USB 4? But USB 2.0, not USB2?
I now have two Macs that I want to connect via Thunderbolt 4. I don't know how to tell if a particular cable will work.
Oh yes USB is complicated. USB4 ports are required to implement USB 2.0, USB 3.2 (but only 5 and 10Gbps are required, 20Gbps is optional), and DP Alt mode supporting at least DP 1.2 for 4K60. Must use USB-C connector. USB 2.0 is the newest version of the original USB with 4 wires (+5V, ground and +/- data pins) with the 1.5, 12 and 480Mbit speeds. USB 3.2 is the newest USB 3.x standard covering the new pins that were added allowing full duplex at higher speeds covering the 5, 10 and 20 Gbps. Then there are the thunderbolt supersets on top of USB4 (apparently USB4 hubs must support thunderbolt, but hosts and devices don't have to). And of course the interesting tunneling abilities of USB4 to allow carrying display traffic and network traffic and various other interesting things. USB started out simple, but sure isn't anymore. -- Len Sorensen
On Fri, 28 Feb 2025 17:01:09 -0500 Lennart Sorensen via talk <talk@gtalug.org> wrote:
On Fri, Feb 28, 2025 at 03:23:07PM -0500, D. Hugh Redelmeier via talk wrote:
<https://everything.explained.today/USB4/> Did you know it is USB4, not USB 4? But USB 2.0, not USB2? I now have two Macs that I want to connect via Thunderbolt 4. I don't know how to tell if a particular cable will work.
Oh yes USB is complicated.
USB4 ports are required to implement USB 2.0, USB 3.2 (but only 5 and 10Gbps are required, 20Gbps is optional), and DP Alt mode supporting at least DP 1.2 for 4K60. Must use USB-C connector.
USB 2.0 is the newest version of the original USB with 4 wires (+5V, ground and +/- data pins) with the 1.5, 12 and 480Mbit speeds.
USB 3.2 is the newest USB 3.x standard covering the new pins that were added allowing full duplex at higher speeds covering the 5, 10 and 20 Gbps.
Then there are the thunderbolt supersets on top of USB4 (apparently USB4 hubs must support thunderbolt, but hosts and devices don't have to).
yes, hosts and devices do not impliment everything but for different reasons so probably the place to start looking for answers is whether the hub/device has implimented x or y
And of course the interesting tunneling abilities of USB4 to allow carrying display traffic and network traffic and various other interesting things. USB started out simple, but sure isn't anymore.
Way back, I think in 2004, I was involved in creating code to support usb for the linux kernel. imho, the direction usb specifications are going in has become political and in favour of darker media streaming agendas. anyway, you can brush up on your usb 1.0 and 2.0 As Military spending is going to be doubling in .ca (and tripling, quadrupling and even 1000% in other geo's) more of us are going to probably work in those environments as everyone is working on 'tech' weapons - I do not see even 3.2 hitting these environments before sometime after 2030 or later :)
participants (3)
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ac -
D. Hugh Redelmeier -
Lennart Sorensen