4 ms·
Except, of course, for Thunderbolt 3, where to get even reasonable lengths you have to pay $$$. https://www.theverge.com/2020/7/27/21339861/apple-thunderbolt-3
by wan23 6y ago
Except, of course, for Thunderbolt 3, where to get even reasonable lengths you have to pay $$$.
https://www.theverge.com/2020/7/27/21339861/apple-thunderbolt-3-pro-cable-specs-price-available https://www.theverge.com/2020/7/27/21339861/apple-thunderbol...
- jeffbee 6y agoWhat's the deal with these prices? Is it just because the connector is so compact? A 2-meter QSFP+ 40-gigabit copper cable is only about $25. https://www.fs.com/c/40g-qsfp-dac-1117 https://www.fs.com/c/40g-qsfp-dac-1117
- wffurr 6y agoThey are "active" cables and so have microcontrollers in them.
- jeffbee 6y agoBut isn’t that an indictment of the whole architecture? 40-gig Ethernet reaches these distances with passive cables. Is it that the Ethernet people have moved the costs into the port and their ports cost more, while the thunderbolt ports cost less and the cables cost more?
- wffurr 6y agoNever seen a consumer motherboard with 40Gb Ethernet. Even 10Gb is rare. One criticism of Thunderbolt is that it already requires a fairly expensive separate controller on the motherboard except for a few Intel chips with built-in TB controllers. Sending that much data that fast is going to cost more somehow or another.
- jeffbee 6y agoRight, just thinking about the end-to-end economics. The TB3 add-in card for my HP workstation costs $200 for 2 ports. HP doesn't market a 40g ethernet card but an Intel model costs $400 at retail, also for 2 ports. Then I need either 2 $25 cables for ethernet or 2 $129 cables for TB3. It's the same price either way. Of course, the two setups don't accomplish the same things; they are comparable only in reach and speed.
- Bud 6y agoOne very major difference is, Thunderbolt's spec requires that this cable carry 100W of power in addition to the 40Gbps of bandwidth.
- pmalynin 6y agoPower over Ethernet is not too far from 100W. Maybe around 70, if I can recall correctly. So the power isn’t the biggest factor I think