Which is what I've been saying all along. I think you're cherry-picking my initial "USB4 v2 mode”
is Thunderbolt 5" comment which could have been better expressed as "USB4 v2
mode”
is Thunderbolt 5
mode" but that was all in response to your post about what
connection mode System Report shows, which
will be USB4v2 for a TB5 connection because the proocols used by TB5 are all part of USB4. My original post did go on to elaborate on TB4/5 being about certification and minimum specs.
USB4 is mozzarella & tomato pizza with a range of sizes and extra toppings, TB4/5 is the MegaPizza 14" Cheese Lover's 3 Cheese Special - but its the same 3-cheese pizza you'd get if you called GoEat and ordered a USB4 with extra cheddar and Swiss (...esp. as everybody gets their dough and toppings from the same 3 wholesalers, bit like USB/TB chipsets).
...because there's no "Thunderbolt 5 mode" it could report - USB4v2
is the connection protocol that all the TB5 features use. 120Gbps asymmetric is part of USB4v2 - it's just not mandatory for USB4v2 branding. System Report is just telling you what protocol is currently in use, it isn't going to provide a forensic analysis of all the specs of your connected gear!
That's probably because the host is
currently connected to the hub in bidirectional 80Gbps (2 x 40 up, 2 x 40 down) mode which is how the hub normally operates - to drive a 120Gbps device it would have to switch to asymmetrical (1x40 up, 3x40 down) mode. At the moment, I believe that 120Gbps mode is purely for super-high-end video displays, not data use. Maybe if you connected a 120Gbps-compatible TB display, system report would show the mode as 120Gbps.
What "up to" speed does it say for unused TB5 ports of your Mac?
OS-level reporting. System report isn't a TB5 certification compliance-testing tool. It's just telling you the current connection mode/protocol - and all of the TB5 features use USB4v2 protocols.
M4 Pro/Max and M3 Ultra Macs have TB5-branded ports so they must meet TB5 minimum specs. Likewise for Apple-branded TB5 cables. You might get fake TB5 cable from some dodgy source, but Apple/OWC/Anker et. al. aren't going to play that game.
Maybe, but impossible to know unless you try connecting a peripheral that actually supports 120Gbps.
I don't think there's any difference in the data-carrying part of passive TB3, TB4 and TB5 cables, and if TB3 cables can
physically do 80Gbps bidirectional they can
physically do 120Gbps asymmetrical (one of the 4 x 40Gbps twisted pairs is just running in the opposite direction). It just comes down to whether the host checks the cable ID and says "no - I won't turn on this feature".
One key difference between TB3 and TB4/5
cables is that, I believe, TB4/5 certification requires 240W power delivery c.f. 100W for TB3, which shouldn't affect data capabilities.
If you want a puzzle for ther ages, try and work out why
this USB4v2 cable isn't sold as Thunderbolt 5 (apart from Satechi maybe noty wanting to pay Intel). Beats me!
satechi.net