[nubinetwork]

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...

[baby_souffle]

> Regular people don't know this stuff...

Regular people also are not buying DACs.

If you are in the line of work where you need to know what SFP is and the difference between DAC and Optical, a quick "what's OM3 vs OM5 and when do I use either?" to your favorite LLM/Search engine will get you sorted.

[xxpor]

I gotta say this is the kind of stuff that LLMs make trivial to answer these days.

[simoncion]

> Regular people don't know this stuff...

Regular people don't know whether to get Cat5, Cat5e, Cat6, or Cat7. So... yeah.

> ...OM3/OM4/OM5? Single mode/Multi mode? LC/SC?...

My answer is OM4, Multi-mode [0], LC. OM3, 4, and 5 will all work at 10gbit for any run you'd expect to make in most houses. I chose cable grade based on what was in stock at the local store. I chose connector type based on what fit into my NICs. I went with multi-mode because it was cheaper than single-mode and I wasn't going to be making multi-km runs.

[0] That's what the "M" in in the cable designation means.

[bigfatkitten]

Go with single mode only for new installs.

Biggest install cost is labour. The cable and optics are cheap now, and with the future (200Gbps+) being multiple wavelengths in parallel[1], we’ve pretty much hit the end of the road for MMF.

[1] https://www.tiafotc.org/ieee-802-3-ethernet-standards-update...

[sekh60]

This is the correct answer, always single mode. It's been the most future proof to date, people just keep figuring out how to cram more and more wavelengths into it.

[simoncion]

> 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, you're "never" hooking that up to a gaming PC.

[bigfatkitten]

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.

[toast0]

You can get boards with pci-e 5.0 x8/x8, which might bottleneck your gpu enough to see on benchmarks, but wouldn't bottleneck your nic, if you have a pci-e 5 nic (which might actually be a 400Gbs nic, whoops)

Anyway, priorities. Nic in the cpu slot, gpu in the chipset slot :p

[ciupicri]

> Regular people don't know whether to get Cat5, Cat5e, Cat6, or Cat7.

What are you talking about. It's right in the manual for some switches like the TP-Link TL-SX105 V4 [1]. It's not even an expensive or fancy one.

    Network Media (Cable)
    100BASE-TX: 2-pair UTP/STP of Cat. 5 or above (maximum 100 m)
    1000BASE-T: 4-pair UTP/STP of Cat. 5e or above (maximum 100 m)
    2.5GBASE-T: 4-pair UTP/STP of Cat. 5e or above (maximum 100 m)
      5GBASE-T: 4-pair UTP/STP of Cat. 5e or above (maximum 100 m)
     10GBASE-T: 4-pair UTP of Cat 6 (maximum 55 m) or STP of Cat 6, 6a, 7 (maximum 100 m)

If you're too lazy to read the manual you could probably ask chatgpt, gemini whatever. Or you could ask the guy from a store. A run of the mill store, not some crazy hobbyist store.

In the worst case you'll buy some overboard Cat 7 cable, but at least things are simple unlike with fiber optics last time I've asked [2]. With cable all you need to know is the speed. You don't have to ask yourself what kind of module you have or maybe you don't even have one. All you need to know is the speed and perhaps the length although I think only "the 1%" will need more than 55 meters :-)

[1]: https://static.tp-link.com/upload/manual/2025/202501/2025012...

[2]: https://news.ycombinator.com/item?id=47901136

[KaiserPro]

The difference between cat5 and cat 6 for installation is quite marked. well it used to be, it might have improved recently.

Because 6 has the plastic separator its much more of a bastard to pull through things. I imagine that 7 is also a dick in that regard because the shielding stops it from bending as readily.

[simoncion]

   Regular people don't know whether to get Cat5, Cat5e, Cat6, or Cat7.

> What are you talking about. ... If you're too lazy to read the [rare] manual [that contains advice on the topic] you could probably ask chatgpt, gemini whatever. Or you could ask the guy from a store. A run of the mill store, not some crazy hobbyist store.

I can query Google, an LLM, or a run of the mill cancer doctor for information on how to treat my stage 1 melanoma. That I can learn how to treat stage 1 melanoma doesn't mean that I know how to treat stage 1 melanoma.

> [Fiber optics are so complicated.] [With copper, all] you need to know is the speed and perhaps the length although I think only "the 1%" will need more than 55 meters :-)

For a 55 meter run, all you need to know is "Buy the cheapest multimode two-strand fiber your vendor has in stock. It's going to have LC ends, so get LC multimode optics.". You don't even have to worry about the speed of the transceivers to use this advice.

As an aside: Wow. That's [0] pricey for a dumbswitch that you also can't ever switch over to fiber. You can get a managed switch with four 10gbit cages, five 1gbit cages, and one 1gbit port for fifty bucks less [1], or a (physically much smaller) managed switch with four 10gbit cages and one 1gbit port for about the same price as that five-port TP-Link dumbswitch. [2]

TP-Link is absolutely raking in the dough on that unit.

[0] <https://www.newegg.com/tp-link-tl-sx105/p/0XP-001U-007G7> (apparent MSRP of 280->300 USD)

[1] <https://www.newegg.com/p/0XP-002R-000Y8?Item=9SIAEFKHB37914> (MSRP 200 USD)

[2] <https://www.newegg.com/p/0XP-002R-00108?Item=9SIB7VEJJD1334> (MSRP 150 USD)