What has less latency, air or wire?

What has less latency, over air or over wire?

I run 75 foot cables with a repeater under my floors, to connect my computer to my living room TV.
In some games I feel the added latency, so was considering over air.

I have a laptop which connects to the router via WiFi (the router is about 15 feet away) and a desktop that connect via a wire to the router, maybe 40 feet of wire. The laptop consistently gets higher speeds when downloading on Steam.

I feel like the latency is around the same but to be fair, I haven’t looked specifically at it.

I suspect the repeater may be the culprit if you’re experiencing a noticeable amount of latency. In principle copper is ~2/3 the speed of light, and wireless should be whatever the speed of light is through whatever medium the EM waves are going through. (I dunno, I’m not a physicist.) In practice, wireless peripherals tend to be very slightly slower, probably due to additional processing. The signal itself is perfectly fast.

Wired is generally a lot faster and more reliable than wireless.

Wireless has to deal with all the other electronic noise around you. If you’re in a suburb, that means dozens of other routers in your vicinity, as well as all the other noise that your cell phones and microwaves and such spit out. And then there’s all that non-electrical stuff that causes problems, like walls and furniture.

But, yeah, the repeater is a major issue. It’s basically halving your bandwidth off the bat. It’s just not efficient at all.

@jpinard , what kind of repeater are you talking about here? Is this for a video signal (like an HDMI repeater), or something else?

I ran ethernet cabling from the router/cable modem in the basement to my wife’s home office upstairs, and the TV boxes in the living room. It’s a small house, so distances aren’t very long, and I didn’t use any sort of repeater or whatever. I’m not sure at what distance you need something like that; might depend on the quality of the cabling as well as distance, maybe?

As long as it’s terminated correctly (and it should be if using standard connectors) ethernet cable should be able to run 100 meters without a repeater. Raw latency over the air is less, but the protocol will dominate. Ethernet has a collision detection mechanism and Wi-Fi doesn’t. Wi-Fi packets have to wait for acknowledgment from the receiver. Ethernet should give better performance in most cases.

Hey man, this is right up my alley!!!

Let me put on my work hat for a moment. I’m going to give you two answers:

  1. Related to physics and science, the actual ~path~ that each of these takes gives the nod to wireless, but only just. Electrons through wires encounter a number of physical things that slow down the rate from, “speed of light,” to something slightly less than that, but still very fast.

  2. However, wireless has a number of things that affect the error free transmission of data across it; signal strength, congestion, signal quality(noise,) multipath, etc. All of these can cause the packet from your gaming laptop to possibly arrive out of sequence or slow/fast/delayed. In general this gets perceived as being slower than a wired connection, as a wired connection is through a switch, typically not interfered with at all from you to where it’s going. Your wireless packet latency must take into account all of these things as it reports a general number back for things like ping times. The variance for wireless on those pings with be greater as well.

All of this is compounded by how many devices you have on each network type, the speed and rated throughput of the devices, and all sorts of other things. Because of the additional issues with wireless, speed for speed, a wired connection will average out much better throughput over time.

75 feet of cable is NOTHING, in regards to network. I want you to think of how quickly flipping a light switch on one side of a warehouse will turn on the light on the other end. You wouldn’t be able to even perceive it most likely. The same for your cables.

I have this for USB - 65 feet

and this for HDMI - 75 feet

I didn’t use a repeater/signal amplifier with my HDMI, just the USB which you can see is part of the cable.

Interesting. Could I somehow have ethernet carry my HDMI and USB signals?

Also wondering if there’s a test I can run on both my office and living room setup to get numbers on the actual latency?

Ah, I thought you were talking about ethernet. For USB you definitely need a repeater and you’ll definitely get unavoidable latency. I don’t really know HDMI.

Very long USB or HDMI cables are iffy at best. I think the official specs for those standards have relatively short cable lengths.

You would probably want something like a special fiber optic USB-C cable from your PC to a USB-C hub/dock near your TV that would provide HDMI and USB connections for video and M/KB, but I think that would require your desktop USB-C port to support video transport. That’s common in laptops but maybe not so common on desktops.

Alternatively, maybe look into something like Moonlight? I think @stusser uses it to stream games to other devices.

@Matt_W @Freezer-TPF Freezer

I found this! But it’s quite expensive (for me).

You’d still need a hub/dock and also to confirm your PC can output video via USB-C. Moonlight is probably a better bet for a clean solution.

I would just use it for USB since I already have my video done via fiber.

Yeah USB fiber extenders are pricey. I’ve used them at work, but too costly for home use for me. Consider downgrading your house so that your cables don’t have to reach so far :)

I’ve been thinking about starting a thread around Moonlight or Steam Link and networking. I’ve tried this but it’s a bit too laggy for me, and I wonder if upgrading my network would help (R6400 AC1750 V1)?

It’s really close to where it might be decent. It would work for turn based stuff, but too laggy for action games like Yakuza 0.

In my case, upgrading my older AC3000 router to a more modern Wifi 6e mesh setup absolutely did help. It also helped PCVR wireless passthrough on Quest 3. I regret waiting so long to upgrade my router.

I’m using Steam Link (via the Apple TV app) and it works really well. I’m looking into giving Moonlight a try, since apparently it supports HDR.

I did powerline networking for a while and it worked great. The best part was no need to run cables.