4 ms·

The max cable Length at that speed is pretty darn short.

amelius 4y ago
What's stopping us from adding a repeater every couple of feet? Transistors aren't expensive and integrating it into the cable shouldn't be too difficult.
- ChrisLomont 4y ago
  120Gbps repeaters will be expensive. Making circuits that fast is incredibly tricky, with power, heat, rf (and more) issues. If you think it's cheap make one and get rich. But it's most certainly not cheap or easy or low cost.
- ip26 4y ago
  I'm sure it's possible, but 40Gbps fiber bundles probably win easily on cost per bandwidth over any significant distance.
- wyager 4y ago
  Transistors that can pass 120gbps are probably expensive as hell, possibly into InP territory. The cheapest way to do this is over OS2 fiber. Look up how much money you have to spend to get 2x 100gbps OS2 PHYs and 2x 100gbps QSFP28 cards.
  - amelius 4y ago
    > Transistors that can pass 120gbps are probably expensive as hell, possibly into InP territory. That's a strange argument, given that USB devices and your USB ports and CPU need a multiple of the amount of transistors in a repeater to process these signals.
    - wyager 4y ago
      Internal busses can operate in parallel, at some fraction of the serial bandwidth. You only need really fast stuff at the PHY. An interleaver/deinterleaver circuit is not much more complicated than the kind of signal shaping hardware you would need multiple copies of in the cable.
- DannyBee 4y ago
  It will be infinitely more expensive and harder than just using fiber. Two transceivers is 350 bucks total for 2km single mode. 200 for multi mode if you want cheapest possible A 4 port switch is about 700 bucks. You could also do 25gb x 4 and aggregate at probably 1/3 price. You could upgrade later, without changing fiber. You could also go with the switch but use 25g transceivers, and upgrade the transceivers later. This is about 60% cost. In a year this will all be half that price. USB4 plus a ton of repeaters plus … is going to dwarf the initial cost of 100g fiber quickly. In 5 years, you will probably be able to run 800g over the same fiber if you are bored. A or aggregate 100g links. You would have to replace all the USB with new USB-9 2x2.4 SE stuff.
  - BonoboIO 4y ago
    * USB-9 2x2.4 SE Gen 3 Plus :D

What's stopping us from adding a repeater every couple of feet? Transistors aren't expensive and integrating it into the cable shouldn't be too difficult.

ChrisLomont 4y ago
120Gbps repeaters will be expensive. Making circuits that fast is incredibly tricky, with power, heat, rf (and more) issues. If you think it's cheap make one and get rich. But it's most certainly not cheap or easy or low cost.
ip26 4y ago
I'm sure it's possible, but 40Gbps fiber bundles probably win easily on cost per bandwidth over any significant distance.
wyager 4y ago
Transistors that can pass 120gbps are probably expensive as hell, possibly into InP territory. The cheapest way to do this is over OS2 fiber. Look up how much money you have to spend to get 2x 100gbps OS2 PHYs and 2x 100gbps QSFP28 cards.
- amelius 4y ago
  > Transistors that can pass 120gbps are probably expensive as hell, possibly into InP territory. That's a strange argument, given that USB devices and your USB ports and CPU need a multiple of the amount of transistors in a repeater to process these signals.
  - wyager 4y ago
    Internal busses can operate in parallel, at some fraction of the serial bandwidth. You only need really fast stuff at the PHY. An interleaver/deinterleaver circuit is not much more complicated than the kind of signal shaping hardware you would need multiple copies of in the cable.
DannyBee 4y ago
It will be infinitely more expensive and harder than just using fiber. Two transceivers is 350 bucks total for 2km single mode. 200 for multi mode if you want cheapest possible A 4 port switch is about 700 bucks. You could also do 25gb x 4 and aggregate at probably 1/3 price. You could upgrade later, without changing fiber. You could also go with the switch but use 25g transceivers, and upgrade the transceivers later. This is about 60% cost. In a year this will all be half that price. USB4 plus a ton of repeaters plus … is going to dwarf the initial cost of 100g fiber quickly. In 5 years, you will probably be able to run 800g over the same fiber if you are bored. A or aggregate 100g links. You would have to replace all the USB with new USB-9 2x2.4 SE stuff.
- BonoboIO 4y ago
  * USB-9 2x2.4 SE Gen 3 Plus :D