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It's crazy to think of the crazy high-speed signals we're now able to send over copper. Think about it: 5Gbit used to only be possible over very expensive hardw
by AceJohnny2 10y ago
It's crazy to think of the crazy high-speed signals we're now able to send over copper. Think about it: 5Gbit used to only be possible over very expensive hardware and very specialized/isolated cabling. Now it's all over the place: it started with PCIe, then Thunderbolt, then USB3, now Ethernet. And this is thanks to the advances in silicon technology that allows us to manufacture PHYs that are both performant to send/receive these signals and cheap enough to include in consumer hardware. It's not just Moore's law that allows this, but technological advances in signal processing.
In fact I've once read that all these high-speed signals are basically re-using the PCIe PHY. Does anyone with more knowledge of that area of tech know any more about it?
- wmf 10y agoPCIe, SATA, SAS, Fibre Channel, Infiniband, and data center flavors of Ethernet are all based on very similar serdes technology that uses multi-GHz binary encoding over shielded cabling. http://www.design-reuse.com/articles/10541/multi-gigabit-serdes-the-cornerstone-of-high-speed-serial-interconnects.html http://www.design-reuse.com/articles/10541/multi-gigabit-ser... 1G/2.5G/5G/10G Base-T Ethernet uses fairly different sub-GHz multi-level encoding over unshielded cabling.
- AceJohnny2 10y agoThanks! That's exactly what I was looking for! I'm surprised that Base-T is unshielded. Cat-5 and more requires shielding over the full cable, however the cable will contain 4 twisted pairs of wire. Are those pairs of wires considered the "unshielded cabling" for the purposes of this application?
- Vendan 10y agoCat-5, Cat-5e, and Cat-6 are all unshielded by default, but there are shielded versions for high EMI environments.
- AceJohnny2 10y agoHuh, I didn't know that. Thanks!
- DannyBee 10y agoThey use differential signaling to reduce noise.