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

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 expensive. And then, there's the big one - PoE. That's why I also ran CAT6A next to each duplex to rooms and they're more or less for APs in the house. Overall it's definitely future proof and fantastic, but also a bit expensive if you wanna engage that fiber through the house. Pulling the cable itself isn't much of a cost at all and I recommend it.

What for? Ethernet is what you ultimately need, because that is what devices such as PCs and WiFi access points use. I experimented with SFP for a while, but ultimately concluded that it isn't worth the effort to add SFP cards to PCs now that that low-power 10G Ethernet chips like the RTL8127 are available. High-end motherboards already have 10G Ethernet and soon lower-end models will too. 2.5G is practically standard already.

There are probably still a lot of cases where you would want PoE though right? Cameras, WAPs, etc.

I have ten gigabits throughout most of my house, and you're right: copper is not happy pushing ten gigs.

My 10 gigabit thunderbolt dongle weighs about a pound, and I think 90+% of that weight is just heatsink. If I've had it plugged in for awhile, if I accidentally touch that dongle it actually hurts because it's so hot. I cannot image that much heat is good for, well, anything.

I have another Thunderbolt dongle that has an SFP+ module, so I ran a fiber line from my switch to my computer, and that runs considerably cooler. That's what I use nowadays.

I would be grateful and happy to have gigabit Ethernet with cat 6A in every room instead of this single landline phone jack and/or coaxial cable. The most important thing is a good conduit in place when the house is built.

> ethernet at 10gbit/s and its really high consumption and heat

Do you mean Ethernet cables get hot? Or just the networking equipment pushing that data.

I ask because I’ve never heard of Ethernet cables getting hot.

you should be putting in conduit -- either smurf tube, emt, sch40, or similar. can pull whatever, and more importantly, if a cable is damaged by an overly zealous gorilla during installation, it can easily be fixed and replaced.

> the off ramp is clearly happening for ethernet

You should be running both.

If you are being smart about it your planning distributed switching (fiber to media boxes with power).

From a pure networking stance, fiber is the way to go. But POE continues to have more and more uses (doorbells, cameras, sensors, lighting controls).

You cannot do PoE over fiber.

You still need to power things.

Often that will mean running both Cat6A and fiber.

You can also use a BananaPi BPI-R3 for reprogramming. And you can “upgrade“ 10 Gbit/s DACs to 25 Gb/s. Details here https://kohlschuetter.github.io/blog/posts/2026/03/22/unlock...

I tend to use fs.com optics, but I’ve heard in high rates (100g plus) that flex optic tend to be more reliable

fiberstore has them as well, plus you can buy modules, DACS and everything programmed to the vendor of choice, including different vendors on each end

Especially handy for specific Intel NICs where they refuse to link up if the module isn't in the driver-allowed list and those modules are hard to come by

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.

Wish apartments would come with those

What about performance and driver support for Linux? Any issues with suspending to memory or disk?

I've got a mix of both running here and definitely prefer the SFP+ part of the world. Couple of neat tricks it enables like the new "invisible" fiber - looks the same like fishing line basically. Unless you're 30cm away and actively looking you can't see it.

Replaced a wifi bridge that way...30m run across multiple rooms & hallway...zero drilling.

I have a RTL8127 NIC from Aliexpress that uses 1 PCIE 4.0 lane, finally a use for those 1x slots and it does pretty good on 10G speeds.

I wish multiple-port 10G PCIe cards with this chip were available. I would immediately upgrade by Debian router from 2.5G to 10G. At the very least I would need a dual NIC.

and the QSW-L3208-2C6T-US is a cheap 8port switch

I'm also using the WAS groupon stick with a huge fan on it. I really wish they would build a proper fan and cooling duct into the stick and power it with the stick itself. It very much seems like a half-assed solution.

fs.com displays wattage ratings on all of their products, pick low watts.

https://www.fs.com/c/gpon-xgspon-sticks-5607 (I think this is what you're looking for?)

I've bought a good bit of 10Gtek stuff over the years. Not sure to what extent they actually are designing their products vs. just acting as a reseller (I think the latter), but either way everything I've bought from them has been quality kit that lasted for years, at a great price.

For a lot of people, because they already have copper in the walls.

You are correct that 10GBASE-T really shouldn't be the default choice, fiber and DAC both have advantages over it. But compatibility is important, and there are a lot of situations where 10GBASE-T is just more convenient.

DAC cables can get expensive, and nobody knows what to buy when it comes to fiber, unless you're running entire spools of the stuff inside buildings... OM3/OM4/OM5? Single mode/Multi mode? LC/SC? Regular people don't know this stuff...

For connecting via say a Macbook Pro, there used to not be Thunderbolt 4 SFP+ interfaces. So, you were pretty limited to some ethernet SFP+ module that you hope would actually work.

Also personally, if you can get away with a copper DAC, I would rather use that instead of fiber because you don't need any special modules.

Access points, for example, expect PoE.

I don't think that's quite true. Unifi 10GbE switches are cheap enough I have a 24 port PoE+++ one in my house and my 3 main WiFi APs are 10GbE connected. My MBP uses a 5Gbps Thunderbolt adapter that runs relatively cool as well. All of this is over the existing Cat5e wiring.

I'd say 10GbE has arrived. It is relatively cheap, most of the time works over existing 1GbE cabling, and gracefully degrades to 5/2.5/1Gb based on conditions when it can't reach 10Gb.

Yes to be 100% guaranteed of getting 10Gb even in bundles of 100 cables running over noisy fluorescent ballasts to a full 100m you need Cat6A but in many environments Cat5e or Cat6 is more than sufficient. It works so well if you fail to get the full 10Gb I humbly suggest you re-do the terminations on both ends before considering replacing the cable.