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Right now I've got my LAN cable from my computer hooked up to a switch, and that cable from my switch goes through my house downstairs to a router. I'm wondering whether the latency will be improved or made worse if I switch on over to a fiber optic cable? In theory it should be faster but because I will have to attach fiber optic to RJ45 converters, they might add more to the latency right?

https://www.arista.com/assets/data/pdf/ ... -Brief.pdf
Looks like it is not worth it. Fiber is just used for longer distances when you want to avoid speed loss or in cases where interference happens.

deama wrote: ↑

05 Dec 2021, 15:38

Right now I've got my LAN cable from my computer hooked up to a switch, and that cable from my switch goes through my house downstairs to a router. I'm wondering whether the latency will be improved or made worse if I switch on over to a fiber optic cable? In theory it should be faster but because I will have to attach fiber optic to RJ45 converters, they might add more to the latency right?

Depends.

The lab tests often tests a spool of cable on the middle of a lab bench. They don't often test in-wall Ethernet runs past your laundry machine, the 200 amp power panel, the refrigerator, the air conditioner, and then finally past the baseboard heater, and finally to your computer. By the time that Ethernet signal hits your computer, it's been assaulted by EMI from your appliances, with the attendant error-correction latencies not published in these research papers.

You can do a fiber run for less than $100 with some cheap gigabit media converters and some cheap standard OM3 fiber. Later on when you want to upgrade gigabit to 10 gigabit, you simply replace the media converters. Or even faster than 10 gigabit, cheap OM3 fiber cable at pennies per foot can be pushed to 100 gigabit, so the OM3 may last the rest of your lifetime.

That can be cheaper than a long expensive CAT6A or CAT7 STP solid copper run that is 100% NEC compliant for legal in-wall installation (e.g. 100+ foot that's not CCA).

Optical fiber is much more immune to EMI than copper, so you might (in some cases) get better latency performance, especially with an Ethernet run passing across lots of electrical devices.

Interference = error correction latency (and/or lost packets) = long borderline Ethernet runs can become laggier than the media converter overhead.

If you're wiring in-wall in a new-build house, across multiple floors, especially adjacent to power wires, then optical is definitely much lower risk. Better futureproofing, better EMI resistance, and cheap modern OM3 fiber that's bend-insensitive is mere pennies per foot or per meter can scale to 10 gigabit and even 100 gigabit. It's worth seriously considering.

Chief Blur Buster wrote: ↑

06 Dec 2021, 04:45

...
If you're wiring in-wall in a new-build house, across multiple floors, especially adjacent to power wires, then optical is definitely much lower risk. Better futureproofing, better EMI resistance, and cheap modern OM3 at pennies per foot or per meter can scale to 10 gigabit and even 100 gigabit. It's worth seriously considering.

My current LAN cables are running through one of the most EMI ridden areas in my house. I have tested my internet in different ways and I don't think there seems to be an issue, but I am not certain.
I recently bought an EMI line tester and plugged into the socket that my switch is currently plugged in and it is looking quite bad, though it wouldn't surprise me as in that area we have the microwave downstairs, the boiler right next, and various other stuff/wires running across.
So was thinking maybe I'll get improvements with fiber optic.

From my calculations, I would need roughly £80 to get everything setup, a 10m long (possibly even longer?) fiber optic cable that's about £14, and the fiber to RJ45 converter, which are quite expensive, about £30-35 per unit, and I would need 2 of those. Does that sound right or is £30-35 for the converter too expensive? My current download speed is at 100Mbps (I have limited it) and I really don't care if I can go higher (I can push it to about 200-300Mbps), I have plenty of speed now, all I care about is latency and stability at this point.

deama wrote: ↑

06 Dec 2021, 06:46

Chief Blur Buster wrote: ↑

06 Dec 2021, 04:45

...
If you're wiring in-wall in a new-build house, across multiple floors, especially adjacent to power wires, then optical is definitely much lower risk. Better futureproofing, better EMI resistance, and cheap modern OM3 at pennies per foot or per meter can scale to 10 gigabit and even 100 gigabit. It's worth seriously considering.

My current LAN cables are running through one of the most EMI ridden areas in my house. I have tested my internet in different ways and I don't think there seems to be an issue, but I am not certain.
I recently bought an EMI line tester and plugged into the socket that my switch is currently plugged in and it is looking quite bad, though it wouldn't surprise me as in that area we have the microwave downstairs, the boiler right next, and various other stuff/wires running across.
So was thinking maybe I'll get improvements with fiber optic.

From my calculations, I would need roughly £80 to get everything setup, a 10m long (possibly even longer?) fiber optic cable that's about £14, and the fiber to RJ45 converter, which are quite expensive, about £30-35 per unit, and I would need 2 of those. Does that sound right or is £30-35 for the converter too expensive? My current download speed is at 100Mbps (I have limited it) and I really don't care if I can go higher (I can push it to about 200-300Mbps), I have plenty of speed now, all I care about is latency and stability at this point.

How did you test your internet in different ways? Nothing will be shown by neither ping test, speedtest, dsl reports test, etc etc.. Depending on the type of switch you own, you can log into its interface and check for an option called "FEC" which is Forward Error Correction, There's different algorithms implemented by different vendors but in general the option to disable it maybe be present in your switch, if not, then try to turn off Auto Duplex mode detection and select 1.0GB full, some switches disable FEC if you turn that off and manually select the Speed & Duplex mode. There should be also an option for you to see the logs on the ports used, FEC logs should be there too.
Anyhow, FEC is there for multiple reasons, one of them is EMI interference, since copper line "Catx Cables" use electrical signals to send information back and forth, an Electromagnetic Interference with the right frequency will corrupt the data being transmitted or received.
I'm not saying that you should turn FEC off I'm just saying for testing purposes see how your copper line is performing without FEC on! Most of the papers that i've read regarding those issues keep on mentioning EMI to be a problem only in industrial areas, hospitals, server rooms and what not, but at the same time, 5 years ago, the only "smart" thing that i had in my room was my TV, and now its just a junk yard of Smart Electronics all interconnected with each other, all using their own power supplies, producing different amount of RF or EMI or even both at different frequencies etc..

deama wrote: ↑

06 Dec 2021, 06:46

and the fiber to RJ45 converter, which are quite expensive, about £30-35 per unit, and I would need 2 of those.

You can get cheap media converters at places like FS.com / Amazon / eBay for closer to $20-$25 each (under 20 pounds sterling). Even branded ones such as TP-Link branded media converters.

However, I realize there might be some shipping/customs/VAT involved to UK, so your 35 quid for an all-cost-included domestic purchase may be actually be reasonable where you are, alas.

Chief Blur Buster wrote: ↑

06 Dec 2021, 12:33

deama wrote: ↑

06 Dec 2021, 06:46

and the fiber to RJ45 converter, which are quite expensive, about £30-35 per unit, and I would need 2 of those.

You can get cheap media converters at places like FS.com / Amazon / eBay for closer to $20-$25 each (under 20 pounds sterling). Even branded ones such as TP-Link branded media converters.

However, I realize there might be some shipping/customs/VAT involved to UK, so your 35 quid for an all-cost-included domestic purchase may be actually be reasonable where you are, alas.

Might give it a go out of curiousity at some point.

Thatweirdinputlag wrote: ↑

06 Dec 2021, 08:45

deama wrote: ↑

06 Dec 2021, 06:46

Chief Blur Buster wrote: ↑

06 Dec 2021, 04:45

...
If you're wiring in-wall in a new-build house, across multiple floors, especially adjacent to power wires, then optical is definitely much lower risk. Better futureproofing, better EMI resistance, and cheap modern OM3 at pennies per foot or per meter can scale to 10 gigabit and even 100 gigabit. It's worth seriously considering.

My current LAN cables are running through one of the most EMI ridden areas in my house. I have tested my internet in different ways and I don't think there seems to be an issue, but I am not certain.
I recently bought an EMI line tester and plugged into the socket that my switch is currently plugged in and it is looking quite bad, though it wouldn't surprise me as in that area we have the microwave downstairs, the boiler right next, and various other stuff/wires running across.
So was thinking maybe I'll get improvements with fiber optic.

From my calculations, I would need roughly £80 to get everything setup, a 10m long (possibly even longer?) fiber optic cable that's about £14, and the fiber to RJ45 converter, which are quite expensive, about £30-35 per unit, and I would need 2 of those. Does that sound right or is £30-35 for the converter too expensive? My current download speed is at 100Mbps (I have limited it) and I really don't care if I can go higher (I can push it to about 200-300Mbps), I have plenty of speed now, all I care about is latency and stability at this point.

How did you test your internet in different ways? Nothing will be shown by neither ping test, speedtest, dsl reports test, etc etc.. Depending on the type of switch you own, you can log into its interface and check for an option called "FEC" which is Forward Error Correction, There's different algorithms implemented by different vendors but in general the option to disable it maybe be present in your switch, if not, then try to turn off Auto Duplex mode detection and select 1.0GB full, some switches disable FEC if you turn that off and manually select the Speed & Duplex mode. There should be also an option for you to see the logs on the ports used, FEC logs should be there too.
Anyhow, FEC is there for multiple reasons, one of them is EMI interference, since copper line "Catx Cables" use electrical signals to send information back and forth, an Electromagnetic Interference with the right frequency will corrupt the data being transmitted or received.
I'm not saying that you should turn FEC off I'm just saying for testing purposes see how your copper line is performing without FEC on! Most of the papers that i've read regarding those issues keep on mentioning EMI to be a problem only in industrial areas, hospitals, server rooms and what not, but at the same time, 5 years ago, the only "smart" thing that i had in my room was my TV, and now its just a junk yard of Smart Electronics all interconnected with each other, all using their own power supplies, producing different amount of RF or EMI or even both at different frequencies etc..

So the way I tested it is I used WinMTR and setup a monitor over to google and ever so rarely I would sometimes get packet drops, a few every hour or so, very low, but still there. I'm not 100% on if it's the cable running through my computer over to my router, or whether it's a problem with the router > exchange point. I did get an EMI line meter a few months ago and did some measurements and found out the area that the LAN cables are going through had the highest noise, some areas are at 350mVp, others at 450mVp, and the area upstairs with the boiler where the LAN cat cable passes through (it's also where my switch is at) goes to a whopping 900mVp. On average, around my house it's between 150-200mVp. So I was thinking maybe that area is causing problems, especially since I have an old cat LAN cable going through it (forgot which cat rating it's at, probably 4 or 5) and it's got a few torn bits.

The socket my computer is plugged in is at 150mVp, however just that one socket isn't enough and I've also got to plug in the monitor etc... so once everything is plugged in, it rises to about 250mVp. However I managed to bring it down by getting an online UPS, so with everything plugged in it's sitting at just 100mVp, which is ok.

deama wrote: ↑

07 Dec 2021, 04:34

So the way I tested it is I used WinMTR and setup a monitor over to google and ever so rarely I would sometimes get packet drops, a few every hour or so, very low, but still there. I'm not 100% on if it's the cable running through my computer over to my router, or whether it's a problem with the router > exchange point. I did get an EMI line meter a few months ago and did some measurements and found out the area that the LAN cables are going through had the highest noise, some areas are at 350mVp, others at 450mVp, and the area upstairs with the boiler where the LAN cat cable passes through (it's also where my switch is at) goes to a whopping 900mVp. On average, around my house it's between 150-200mVp. So I was thinking maybe that area is causing problems, especially since I have an old cat LAN cable going through it (forgot which cat rating it's at, probably 4 or 5) and it's got a few torn bits.

Few every hour = could be as simple as the refrigerator compressor cycling or a heater cycling.

Also, most of the time (though not all), the interference level on your power outlet is less important than the interference on the Ethernet network, this is because your power supply in your gaming rig is much better at rejecting interference than the Ethernet port on the motherboard. However, YMMV.

Whac-a-mole is often >90% do-nothing actions and <10% it-helps actions, so it's a matter of how much time you wish to invest in a very opaque black-box endeavour of attempting to have a cleaner EM area for your computer.