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I thought that the primary feature of Thunderbolt was DisplayPort signaling. What makes it Thunderbolt vs USB-C if it doesn't have DP support?

by Osiris 5y ago

eropple 5y ago
So Thunderbolt 2 included a DisplayPort signaling layer but (AFAIK; may be wrong) Thunderbolt 3 does not -- instead, the hardware must implement the USB-C Alternate Mode for DisplayPort (and in turn is also implementing the USB-C Alternate Mode for Thunderbolt; it's not USB, at least not in USB3). Thunderbolt's main draw is being "PCIe on a wire".
- thaumasiotes 5y ago
  My port is advertised as "Thunderbolt 3/USB 3.2 Gen 1 Type-C port with DisplayPort with alt mode". I guess the problem is that it can't speak whatever version the cable understands? The cable says "thunderbolt 3 compatible". And like I said, the same cable worked fine with the same monitor and a previous Dell laptop. :-/
  - eropple 5y ago
    That sounds like it should work, yeah. USB-C alternate modes should work over any TB3 cable (as far as I know). That's weird.
    - rubatuga 5y ago
      They won’t work over active thunderbolt 3 cables
      - eropple 5y ago
        Is that true? Hunh, I was unaware. So a TB3 dock with DisplayPort is handling the display protocol? Is there a standard driver on the OS side?
  - vxNsr 5y ago
    That's crazy, I just got a new laptop from work, a lenovo instead of a dell, the dock is still an older dell thunderbolt dock, and it refuses to correctly work with the laptop. My (3) monitors show up but ethernet and usbs all cycle in and out. I kinda expected it bec the dock had a lot of problems even with dell laptops I eventually got it to work with mine but I know it got so bad dell stopped selling it pretty quickly. Now I need to shell out $400 to lenovo for a new dock that will (hopefully) support 3 monitors at 1080p60hz. I feel like thunderbolt has gotten to the point that you could legitimately make a great side hustle on affiliate links from in-depth usb-c and thunderbolt accessory reviews.
    - eropple 5y ago
      That sucks - but I can attest that the Lenovo Thunderbolt dock is very solid (I have one of each generation).
- rubatuga 5y ago
  Not true, thunderbolt 3 can carry up to 8 DisplayPort lanes, something usb-c alternate mode cannot do. Both can coexist
  - eropple 5y ago
    Interesting - I must have misunderstood. Is there a good protocol breakdown of the USB-C to Thunderbolt changes and switch-over? (I assume there has to be, as USB4 brings them closer together?)
deleted 5y ago
[deleted]

I thought that the primary feature of Thunderbolt was DisplayPort signaling. What makes it Thunderbolt vs USB-C if it doesn't have DP support?

by Osiris 5y ago

I thought that the primary feature of Thunderbolt was DisplayPort signaling. What makes it Thunderbolt vs USB-C if it doesn't have DP support?

eropple 5y ago

So Thunderbolt 2 included a DisplayPort signaling layer but (AFAIK; may be wrong) Thunderbolt 3 does not -- instead, the hardware must implement the USB-C Alternate Mode for DisplayPort (and in turn is also implementing the USB-C Alternate Mode for Thunderbolt; it's not USB, at least not in USB3). Thunderbolt's main draw is being "PCIe on a wire".

thaumasiotes 5y ago
My port is advertised as "Thunderbolt 3/USB 3.2 Gen 1 Type-C port with DisplayPort with alt mode". I guess the problem is that it can't speak whatever version the cable understands? The cable says "thunderbolt 3 compatible". And like I said, the same cable worked fine with the same monitor and a previous Dell laptop. :-/
- eropple 5y ago
  That sounds like it should work, yeah. USB-C alternate modes should work over any TB3 cable (as far as I know). That's weird.
  - rubatuga 5y ago
    They won’t work over active thunderbolt 3 cables
    - eropple 5y ago
      Is that true? Hunh, I was unaware. So a TB3 dock with DisplayPort is handling the display protocol? Is there a standard driver on the OS side?
- vxNsr 5y ago
  That's crazy, I just got a new laptop from work, a lenovo instead of a dell, the dock is still an older dell thunderbolt dock, and it refuses to correctly work with the laptop. My (3) monitors show up but ethernet and usbs all cycle in and out. I kinda expected it bec the dock had a lot of problems even with dell laptops I eventually got it to work with mine but I know it got so bad dell stopped selling it pretty quickly. Now I need to shell out $400 to lenovo for a new dock that will (hopefully) support 3 monitors at 1080p60hz. I feel like thunderbolt has gotten to the point that you could legitimately make a great side hustle on affiliate links from in-depth usb-c and thunderbolt accessory reviews.
  - eropple 5y ago
    That sucks - but I can attest that the Lenovo Thunderbolt dock is very solid (I have one of each generation).
rubatuga 5y ago
Not true, thunderbolt 3 can carry up to 8 DisplayPort lanes, something usb-c alternate mode cannot do. Both can coexist
- eropple 5y ago
  Interesting - I must have misunderstood. Is there a good protocol breakdown of the USB-C to Thunderbolt changes and switch-over? (I assume there has to be, as USB4 brings them closer together?)

deleted 5y ago

[deleted]