Backwards Compatible ?

[raid25885]

Is Thunderbolt 4 really backwards compatible with USB 3.2 2x2 such as Samsung T9 and Crucial X10 Pro. Some say it is, others say it isn't. 

[Levent]

There is a very good table on the wikipedia page of USB4.

https://en.wikipedia.org/wiki/USB4

[Alex Atkin UK]

10 minutes ago, raid25885 said:

Is Thunderbolt 4 really backwards compatible with USB 3.2 2x2 such as Samsung T9 and Crucial X10 Pro. Some say it is, others say it isn't. 

AFAIK no, this would not be backwards compatibility as Thunderbolt is not USB, it just happens to usually share a USB port.  The same way you can send DisplayPort over a USB-C port, but its an entirely different protocol.

They key is some devices may support USB and Thunderbolt, given its using the connector and Thunderbolt is designed to work on a port that also supports USB.

 

3 minutes ago, Levent said:

There is a very good table on the wikipedia page of USB4.

https://en.wikipedia.org/wiki/USB4

How I utterly despise the mess all the standards bodies have led us into with so many "optional" features, so you never know wtf you're getting.

[raid25885]

And yet Thunderbolt 4 supports the USB 10Gbps and not this ? Its as if it specifically dont want to support the 20 gbps. How will people use the full 20 gbps in Samsung T9 and Crucial X10 Pro since more Windows laptops have Thunderbolt 3/4 ports than USB 3.2 2x2 ports ?!

[Alex Atkin UK]

4 hours ago, raid25885 said:

And yet Thunderbolt 4 supports the USB 10Gbps and not this ? Its as if it specifically dont want to support the 20 gbps. How will people use the full 20 gbps in Samsung T9 and Crucial X10 Pro since more Windows laptops have Thunderbolt 3/4 ports than USB 3.2 2x2 ports ?!

Seems I was wrong:

https://www.intel.com/content/www/us/en/architecture-and-technology/thunderbolt/thunderbolt-4-vs-usb-c.html

 

They make it sound like a device validated as Thunderbolt 4 HAS to support all USB 4 speeds.

[raid25885]

I have emailed Crucial and Samsung whether or not ThunderBolt 4 actually supports USB 3.2 gen 2x2 aka 20 Gbps and they said it "SHOULD". That does not say anything at all

[saintlouisbagels]

Boy you'd have a migraine if you were in the Apple M1/M2 ecosystem.

All of the ports are Thunderbolt 3 / Thunderbolt 4 BUT they don't support USB 20gbps, and it's very convoluted getting USB 10gbps to work.