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Comment by sixdonuts | Hacker News Reader

Yep, 10gb over copper is not power efficient so any savings you get from getting a cheap 10gb switch will just go to your power bill. Most cost effective and flexible is a used 25gb switch. Most 25gb switches can do 1/10/25gb. 10gb networking has been dead for over 10 years.

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Interesting observation about power use. How close do you think we are to it being practical to wire your whole home with fiber instead of CAT6 or whatever? If you're providing all your own equipment, are willing to purchase a high-end splicer for maintenance, etc.

For laptops I assume you need USB/Thunderbolt adapters. (Still no SFP+ or SFP28 module for Framework?)

For desktops you'd use an SFP28 card (taking up a PCIe slot).

For devices like Raspberry Pi's, etc. you'd use... local RJ45 switches with optical uplink ports?

Wiring ports for humans to use in a flexible and future proof manner (as in a single family home, for instance) gains a lot of utility with PoE.

The convenience and flexibility of PoE would always push me towards copper wiring.

You can just do a mix.

Most of my devices only need 1G or even 100Mbps. No reason to switch to fiber. 1G/2.5G copper ports don’t use that much power.

For 10G+ things, it’s fiber or DAC first if possible then RJ45 if it’s the only option.

Then my backhaul between rooms is just single mode fiber, good up to 800G. Plug in a small switch at the end and you go back to RJ45 and PoE.

I only have 10G though (to transfer large files/RAWs between my computer and my storage). Something faster would be nice because NVMe SSDs can go 50G+ but that equipment is pricey and power hungry.

If you need 1G or 10GB over copper you can just use a SFP or SFP+ media converter in a 25GB SFP28 switch port. If you have a POE requirement, say for video cameras you either use a dedicated 1GB POE switch or power injector. A 10GBASE-T (RJ-45 copper) switch consumes 3-12 watts per port and a 24 port switch will idle at 50 to 60 watts and run hot. SFP+ and SFP28 ports use under 1 watt per port. I would never recommend a 10GBASE-T copper switch for any use case in this day and age, home or enterprise.

>10gb networking has been dead for over 10 years.

Not even close to being true, unless you specifically mean 10Gbps over twisted pair (Cat6/7) cable. SFP+ is the default on a ton of network gear still.

I think the point he is making is that the industry first went with a 10g single link, and then 40g over 4 links. Then they figured out how to do 25g over a single link, and 100g over 4 links. Those 25g/100g are common for enterprise switches. It might be fairer to say 40g is dead, 10g still has use cases.

Edit to add: If you want an example, these are the NVidia ConnectX nics available from FS.com, the lowest end one is 25g, then 100g, 200g etc.

https://www.fs.com/uk/c/nvidia-ethernet-nics-4014

What they mean is that the cost per bit both capex and opex/power is worse for 10G than 25G for a while now as long as you talk about new hardware.

We're at the point where 25GBaud PAM4 is being replaced by 50GBaud PAM4. That's 50 to 100 Gbit/s.

But iirc the use of PAM4 for the faster ones than "only" 25Gbit/s lanes is a hindrance to managing bottom-barrel price-per-bit. PCIe 3 was 8, PCIe4 was 16, and PCIe 5 is 32 GBaud with a line code basically like the 10+ Gbit/s Ethernet links (well, it's 66b/64b for Eth and 130b/128b for PCIe).

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