10Gb/s Ethernet: switching to a Broadcom SFP+ module • Hacker News Board

Re: 10Gb/s Ethernet: switching to a Broadcom SFP+ module

#171

Post by chadgpt3 » Mon, Jun 22, 2026, 3:59 PM UTC

Keyframe wrote: post #52

PaulKeeble wrote: post #27

I feel like we have moved into the era now where if you were putting cabling in the walls for networking you should be choosing fibre now. Not necessarily because we are definitely at the stage where the home needs it, but because the off ramp is clearly happening for ethernet at 10gbit/s and its really high consumption and heat. Switching to fibre after 2.5gbit/s seems like the thing to do now and plenty of us now h…

I did just that relatively recently in a house we bought. OS2 single mode duplex throughout the house, all converging to a trunk which is available in three locations for equipment. It's basically future proof, but also has its own well, things. You can't really plug into a duplex (I wish though), you have to put a small switch to it with SFP+ or 28 or whatever the speed you want. Higher speed switches are also a tad…

Why can't you plug and unplug duplexes?

Re: 10Gb/s Ethernet: switching to a Broadcom SFP+ module

#172

Post by chadgpt3 » Mon, Jun 22, 2026, 4:00 PM UTC

andwur wrote: post #76

tombert wrote: post #57

Earlier quoted context omitted.

I use Cat 8. The cables themselves don't get too hot, but the dongles themselves seem to get really hot. I'm assuming that's a known issue given the size of the heatsinks on them.

Unfortunately that's non-DAC copper cabling life it seems. They build them to work at the rated speed at the maximum rated distance (on the transceiver, not the spec) and none of them appear to link train to reduce the power output over shorter runs. If you use a DAC they usually run cool, and optical is even cooler.

DAC should be the coolest but it's only for very short distances.

Re: 10Gb/s Ethernet: switching to a Broadcom SFP+ module

#173

Post by tcdent » Wed, Jun 24, 2026, 5:21 PM UTC

tuetuopay wrote: post #58

tcdent wrote: post #18

If you are implementing 10 GBE at distances less than 5-7 m, I highly recommend standardizing on DAC cabling. It removes the need for these kinds of conversions that create these kinds of heat signatures.

So much this. The rule of thumb is: avoid SFP-RJ45 converters at all costs, you'll be burned by them (literally and figuratively). They all are little snowflakes. Compatibility is hit-or-miss. They run hot. They eat more power. They're finnicky. Heck, they plain out lie about what they are (I've got some that pretend to be fibre with 3m of copper, sure). So yeah, DAC it is for patch, fibre for anything more.

I would also add that the high-quality ones are quite expensive, and that I found incorporating an RJ45 switch with an SFP uplink was more economical for the cases that needed RJ45 (or gigabit) connectivity.

Re: 10Gb/s Ethernet: switching to a Broadcom SFP+ module

#174

Post by simoncion » Thu, Jun 25, 2026, 4:12 AM UTC

bigfatkitten wrote: post #67

simoncion wrote: post #44

Earlier quoted context omitted.

> Biggest install cost is labour. Okay? If I had to run cabling through a wall, I'd make sure the guy sets it up so that I can use the cable he installs to pull new later. My time's free when I'm doing something that I don't mind doing, and I don't mind easy cable pulls. > ...(200Gbps+)... Don't you need 16x PCIe 4.0 for those guys? With everything other than workstation and server boards having exactly one 16x slot,…

MMF cable is quite a bit more expensive than SMF. The cost savings used to be in optics, but that distinction has fallen away. Everyone needs a hobby, so if you want to replace the cable later on nobody’s going to stop you. There was a time when we couldn’t buy a PC that could saturate 1Gbps ethernet, and that time wasn’t that long ago. Your cabling plant will outlive any hardware you buy today.

> The cost savings used to be in optics, but that distinction has fallen away.

So, it has... and fairly recently, too. If only I'd decided to do my home buildout six years later than I did!

It makes me wonder if transceiver longevity or reliability have been compromised, but I suppose that's only a thing you find out after a decade or so.