Comment by Aurornis | Hacker News Reader

Comment by Aurornis | Hacker News Reader

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> Meanwhile, low-end computers ship with a dozen 10+Gbit class transceivers on USB, HDMI, Displayport, pretty much any external port except for ethernet, and twice that many on the PCIe backbone. But 10Gbit ethernet is still priced like it's made from unicorn blood.

You really can’t think of any major difference between 10G Ethernet and all of those other standards that might be responsible for the price difference?

Look at the supported lengths and cables. 10G Ethernet over copper can go an order of magnitude farther over relatively generic cables. Your USB-C or HDMI connections cannot go nearly as far and require significantly more tightly controlled cables and shielding.

That’s the difference. It’s not easy to accomplish what they did with 10G Ethernet over copper. They used a long list of tricks to squeeze every possible dB of SNR out of those cables. You pay for it with extremely complex transceivers that require significant die area and a laundry list of complex algorithms.

There was a time when FFE, DFE, CTLE, and FEC could reasonably be considered an extremely complex bag of tricks by the standards of the competition. That time passed many years ago. They've been table stakes for a while in every other serial standard. Wifi is beating ethernet at the low end, ffs, and you can't tell me that air is a kinder channel. A low-end PC will ship with a dozen transceivers implementing all of these tricks sitting idle, while it'll be lucky to have a single 2.5Gbe port and you'll have to pay extra for the privilege.

No matter, eventually USB4NET will work out of the box. The USB-IF is a clown show and they have tripped over their shoelaces every step of the way, but consumer Ethernet hasn't moved in 20 years so this horse race still has a clear favorite, lol.

You explained why 10G Ethernet cables are expensive, but why should it be so expensive to put a 10G-capable port on the computer compared to the other ports?

Did you completely misunderstand OP? The 10G Ethernet cables are not expensive. In a pinch, even your Cat 5e cable is capable of 10G Ethernet albeit at a shorter distance than Cat 6 cable. Even then, it can be at least a dozen times longer than a similar USB or HDMI or DisplayPort cable.

I did misunderstand it, because looking at it again now, they spent the entire post talking about how difficult it is to make the cables, except for the very last sentence where they mention die area one time, and it’s still not clear that they’re talking about die area for something that’s inside the computer rather than a chip that goes in the cable.

> Look at the supported lengths and cables. … relatively generic cables. Your USB-C or HDMI connections cannot go nearly as far and require significantly more tightly controlled cables and shielding. … They used a long list of tricks to squeeze every possible dB of SNR out of those cables.

Their point was those systems like hdmi, bits of usb-c etc put the complexity is very expensive very short cables.

Meanwhile a 10g port on my home router will run over copper for far longer. Not that I’m a fan given the power use, fibre is much easier to deal with and will run for miles.

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