Comment by dual_dingo
4 years ago
I guess at some point optical will be the only way forward.
Having more data lines in a serial bus is interesting, as the whole reasoning to go from parallel lines (e.g. Centronics, ATA/SCSI or ISA/PCI buses) to serial (SATA/SAS, PCIe, USB) was that coordinating multiple data lines got impossible due to physical limitations where e.g. minimal differences in cable lengths started to matter).
Multiple serial busses, each with its own clocking and buffer, so that the combined data is extracted synchronously at the end. The crosstalk is still a problem but there are ways around that: different twist rates for different pairs for instance.
> I guess at some point optical will be the only way forward.
Maybe. Though Infiniband's currently at 100Gbps per lane on a 1.5 meter passive cable. And active cables can give you a moderate boost while still on copper.
that's a giant QSFP+ cable (I think mine are at least 3/8") with tons of shielding and a terrible bend radius though.
And my cables all have a "10 plug/unplug cycle lifespan" sticker on them - it undoubtedly will go for longer in practice but it's not designed for USB-style usage where you might plug and unplug your phone a dozen times a day as you charge it.
Commercial design concerns are very different from consumer design concerns, basically. Phones would probably be easier if we had a 1/2" x 1/2" x 1.5" connector with a shielded connector body! ;)