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I think I have a decent understanding of the bandwith provided by various TB/USB standards, but this article was all over the place and actually made me doubt t

I think I have a decent understanding of the bandwith provided by various TB/USB standards, but this article was all over the place and actually made me doubt the information I've researched in the past for my home desk setup. And this article somehow misses the most interesting aspect of the USB 4.0 Version 2 announcement: retroactive bandwidth upgrades to existing cables. (https://www.theverge.com/2022/9/1/23332838/usb-4-version-2-80-gbps-thunderbolt https://www.theverge.com/2022/9/1/23332838/usb-4-version-2-8...) That might just be a misunderstanding as well, though. I get the impression that the USB folks aren't very discerning about their terminology in press releases. They could really use an editor to avoid this kind of confusion.

CharlesW 4y ago
> And this article somehow misses the most interesting aspect of the USB 4.0 Version 2 announcement: retroactive bandwidth upgrades to existing cables. This is noted in the “USB4 Version 2.0” section. “…it's supposed to enable up to 80Gbps over USB-C through a new physical layer architecture that uses ‘newly defined’, as the USB Promoter Group put it, 80Gbps USB-C active cables and the 40Gbps USB-C passive cables that already exist today.”
- dont__panic 4y ago
  Nice catch. I feel like this deserves way more discussion, though -- how are they doubling the throughput of existing cables?!?! I wonder if software updates could also upgrade existing USB4 interfaces, too.
  - CharlesW 4y ago
    > I feel like this deserves way more discussion, though -- how are they doubling the throughput of existing cables?!?! Going back to the press release¹, I'm wondering how much weight "up to" carries. That is, I'm guessing that reliable 80 Gbps operation will require new, active USB-C cables, even though existing cables may realize some benefit. "Up to 80 Gbps operation, based on a new physical layer architecture, using existing 40 Gbps USB Type-C passive cables and newly-defined 80 Gbps USB Type-C active cables." ¹ https://www.businesswire.com/news/home/20220901005211/en/USB-Promoter-Group-Announces-USB4%C2%AE-Version-2.0 https://www.businesswire.com/news/home/20220901005211/en/USB...
  - t-3 4y ago
    Probably the encode/decode ASIC can be upgraded due to process improvements (this is why wifi an ethernet improvements see such steady improvements - Moore's Law). Drivers and firmware probably improve incrementally as well.

CharlesW 4y ago

> And this article somehow misses the most interesting aspect of the USB 4.0 Version 2 announcement: retroactive bandwidth upgrades to existing cables. This is noted in the “USB4 Version 2.0” section. “…it's supposed to enable up to 80Gbps over USB-C through a new physical layer architecture that uses ‘newly defined’, as the USB Promoter Group put it, 80Gbps USB-C active cables and the 40Gbps USB-C passive cables that already exist today.”

dont__panic 4y ago
Nice catch. I feel like this deserves way more discussion, though -- how are they doubling the throughput of existing cables?!?! I wonder if software updates could also upgrade existing USB4 interfaces, too.
- CharlesW 4y ago
  > I feel like this deserves way more discussion, though -- how are they doubling the throughput of existing cables?!?! Going back to the press release¹, I'm wondering how much weight "up to" carries. That is, I'm guessing that reliable 80 Gbps operation will require new, active USB-C cables, even though existing cables may realize some benefit. "Up to 80 Gbps operation, based on a new physical layer architecture, using existing 40 Gbps USB Type-C passive cables and newly-defined 80 Gbps USB Type-C active cables." ¹ https://www.businesswire.com/news/home/20220901005211/en/USB-Promoter-Group-Announces-USB4%C2%AE-Version-2.0 https://www.businesswire.com/news/home/20220901005211/en/USB...
- t-3 4y ago
  Probably the encode/decode ASIC can be upgraded due to process improvements (this is why wifi an ethernet improvements see such steady improvements - Moore's Law). Drivers and firmware probably improve incrementally as well.