Optical cable to my PC

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Octopuss

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We will be doing a complete rework of wiring in our flat, and when we're at it, I want to redo the networking as well. For everything else in the house, nothing's going to change, but I was thinking I'd like to have optical connection to my own PC. We have 10Gb switch with three free SFP+ slots and I have also bought Mellanox Connect-X 3 last year with this upgrade in mind.
Now I'm far from a networking guy, so could anyone confirm that all I need is someone to install two optical sockets and an optical line and two DAC cables?
 
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DavidWJohnston

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For short runs between switch and NIC, use DAC cable(s).
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For longer runs between rooms, use fiber, like duplex LC multimode OM3, and wall plates, with patch cords. (Not DACs)
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Between SFP+ port and fiber, you need a transceiver:
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There are a LOT of options when it comes to these things. If you're planning to stick with 10G or possibly 25G in the future, duplex LC OM3 multi-mode is fine, and fairly cheap. Multi-mode fiber is usually used for short runs, and the transceivers are cheaper.

Single-mode fiber itself is cheaper, and is future-proof, but transceivers are more expensive. For short runs between rooms, MM is good.

There are also AOCs (Active Optical Cables) that are like DACs but super long with permanently attached transceivers. You can use these, but then you have to fish the whole transceiver end through your wall instead of the tiny LC connector.

Check out fs.com for new equipment.
 

mattventura

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Personally, I advocate for SMF - you pay a little more for transceivers now (quick ebay search shows $13 vs $6 for 10g), but you're future-proofed to 100g and beyond. Buy once, cry once. I'm assuming that if you're redoing wiring in your flat, you intend to stay there for a while, so it's your call as to whether that's worth it.

Only complication I can see is that some switches won't support third party SFPs, so you may be stuck paying significantly higher prices for the transceivers if it's one of those.
 

DavidWJohnston

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@mattventura Yeah I can't argue with that, lots of good reasons for using SM for a new install.

On second thought it might be convenient having SM too, in the event you get PON fiber service in your place, you could re-locate your modem, of course with the right APC/SC adapters. If you're ripping the walls apart, may as well run some extras.
 
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Samir

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And while you're at it, run at least 2x more runs than you think you will need and to 2x as many places. The cable and extra runs are cheap compared to having to run an extra later. We wired my parent's house in the early 1990s with 400Mhz rated ethernet wire that was 2x as expensive as the next step down. It's done great since that was nearly predating wifi and pre-dated the cat5 spec, and yet runs gigabit great today 30+ years later. Probably will be able to run 2.5Gb too. We also did many runs per room, up to 4--2x on each side as well as rg6 coax which has been handy as well. Bottom line, run the best you can and as many as you can and you'll get some serious life out of it. :)
 
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Octopuss

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Well the title might be confusing, but I though I made it clear in the post.
I want optical connection to my PC. The same concept as copper but optical.
There is a switch with SFP+ ports and a NIC I bought in past that has SFP+ as well.
Don't I just need someone to place two optical sockets in both rooms and two DAC cables?
 
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Octopuss

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I was also told I can do 10Gb over regular copper, but I'd need to add a transceiver to the switch, which consumes more power and supposedly gets hot, and I'd need rather expensive NIC in the PC, which seems like a waste of money.
 
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TonyArrr

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So DACs only work directly from computer to switch, switch to switch, or computer to computer, because they have the SFP module fused to each end. Saves a lot in power but limited range.
If your switch and PC are in different rooms, you would install optical transceivers in the PC and and switch, and run SM or MM from each to their walls and though to walls.
You can’t run a DAC from a SFP slot to a wall
 

Railgun

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I was also told I can do 10Gb over regular copper, but I'd need to add a transceiver to the switch, which consumes more power and supposedly gets hot, and I'd need rather expensive NIC in the PC, which seems like a waste of money.
For copper, depending on your switch you may or may not need a transceiver. In your case, you do. Some switches have RJ45 10Gb ports. These are usually smaller, desktop models. For a single port, the power consumption is not a conversation to worry about. Nor is the heat.

As mentioned, YMMV on whether it will work over copper. I have some relatively short length of 5E throughout the house. My patches are Cat8 and have no issues with 10Gb over copper.

If you want optical, you'd need a NIC for your PC unless for some reason the motherboard has an SFP slot, which generally you don't see unless it's a server. DACs are nothing more than pre-terminated transceivers on either fiber or copper. You use these for direct connectivity between devices, not through structured cabling.

In short, if you want optical, structured cabling, either via singlemode or multi-mode doesn't ultimately matter, usually LC termination. You'll have an LC patch cord from the wall plate or however they deliver it to your PC's NIC.

I'd do something different, but that's me.
 
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Stephan

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Ethernet over copper is popular because you only need an LSAplus for 5 bucks and not a fiber crimping set for 1400:

If this is your home forever (beyond retirement), I'd say go for single mode. For new builds, keep your options open! Always install empty pipes so you or your kids can later retrofit 1 TBit/s crazy mode sockets.

In your case with only 10 Gbps either use 10GBase-T SFP+ modules (with adapter for ConnectX3) or leave the CX3 aside and just get a 10 Gbps card and one SFP+ transceiver for the switch and you're done. Cat6 fed from SFP+ transceivers are spec'ed to 30m length, not 100m.
 
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Octopuss

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So DACs only work directly from computer to switch, switch to switch, or computer to computer, because they have the SFP module fused to each end. Saves a lot in power but limited range.
If your switch and PC are in different rooms, you would install optical transceivers in the PC and and switch, and run SM or MM from each to their walls and though to walls.
You can’t run a DAC from a SFP slot to a wall
Oh, ok. I guess I will simply leave it to my ISP who would do the job. Hopefully it won't be costy.
 
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DavidWJohnston

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Ok, that sounds reasonable. One thing that may be unclear is SFP+ is not optical - It is an electrical socket. A DAC cable is not optical, it is copper.

It's only when you plug a transceiver into an SFP+ port that you get optical. AOC cables (like DACs but really long) have optical transceivers built-in at each end which are non-removable.
 
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Railgun

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It's only when you plug a transceiver into an SFP+ port that you get optical.
That's inaccurate.

SFP/SFP+ can be copper or optical termination.

DACs, while the terminology may be used incorrectly or not, can be simplified as a cable, optical or copper, with pre-terminated transceivers. No need to muddy the waters for the purposes of this discussion.
 
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DavidWJohnston

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Thanks for the feedback @Railgun, I didn't think I was muddying anything - SFP+ is an electrical connection. The only way you can get optical from it is to plug in a transceiver. AOCs (optical DACs) have built-in transceivers, and by using them you are plugging them in. Without a transceiver, no optical.

You need 2 optical patch cables, 2 wall plates, a long fiber run to stretch between your rooms, and 2 transceivers.

Edit: By the way, I can understand wanting optical "just because", I bought a fusion splicer as a toy for my homelab. Well OK, to learn too.
 
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