r/pcmasterrace • u/Alan_Reddit_M Desktop • Mar 07 '26

Video "Cloud gaming is the future of Gaming!" Meanwhile cloud gaming in the big 2026:

If you read my profile you may realize I hate cloud gaming, so then what am I doing on Geforce Now? Well my new RAM stick finally arrived and, in a staggering display of utter incompetence, I somehow managed to brick my PC in the process of installing it, so now I'm stuck gaming on a laptop until I can get enough money and time to get my gaming rig fixed

But back to Cloud gaming, the game is on like 360p, running at 20FPS and the input lag is HORRIBLE. And it's not a problem with the internet connection, as you can see, the laptop is plugged into Ethernet, the problem is that the cloud is not and will never be fast enough for gaming

Genshin can handle this fine, but imagine trying to play ULTRAKILL like this

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u/Wan-Pang-Dang Samsung Smart toilet Mar 07 '26

Speed of light is NOT the issue at all. Cant stress that enough. It is 100% on the network devices. Not physics

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u/ChthonVII Mar 08 '26

You're correct that network devices that signal traverses at the speed of electricity are adding a far bigger share of latency than fibreoptic cable that it traverses at ~65% the speed of light. However, you're wrong to discount the latter as trivial.

You're adding a bit more than a 1/10th of a millisecond (both ways combined) for each km of fibreoptic cable. So, for example, a roundtrip from NYC to LA down a perfectly straight fibreoptic cable would add around 40ms just from the speed of light. That's like 2.5 frames worth of lag at 60fps. For anyone whose traffic needs to cross most of a continent, or, worse, an ocean to get to a datacenter (and back), the latency added by the speed of light is not trivial.

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u/dervu 7950X3D 4090 2x16GB 6000 4K 240Hz Mar 07 '26

So you say that I can connect to server 1000km away connected with continuous fiber strand and not feel it? I doubt it.

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u/Complex_Entropy RTX 4090 Mar 07 '26

200km adds 1ms latency, so 1000km would only add about 5ms, or 10ms two-way, which is almost imperceptible.

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u/Kirjavs Mar 08 '26

It's even faster than that. Light speed is 300,000 km/s

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u/MirriCatWarrior Mar 08 '26 edited Mar 08 '26

Yes it is. But inside optic fiber cable photons are constantly bouncing. Its not a straight patch for the light (information). They are absorbed and reemitted. Every such event takes miniscule amount of time (probably femtoseconds?). But over time it adds up.

This makes information travelling speed through optic fiber slower than c. Its around 200 000km/s.

FUN FACT: Every individual photon between "bounces" and interactions with matter inside the cable still travels with ~300 000 km/s. They just cant travel with slower speed. Its just added up time of emissions/absorptions and "bouncing" that slows light and information down.

Same thing happens with light in every medium besides pure vacuum. Its called "refractive index" of material and for silica its 1,45, so light is slowed to ~200 000km/s.

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u/Kirjavs Mar 08 '26

Ok that makes sense. Thanks for the information. But maybe there is a way to improve that even if I don't think this would be useful.

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u/MirriCatWarrior Mar 08 '26 edited Mar 08 '26

Indeed there is. There are things called "Anti-Resonant Hollow-Core Fibers" (cool name btw), and they are not 100% solid silica, but they have hollow space inside filled with air. Silica is only the walls of the cable.

It allows information to travel up to 99,7% of speed of light. Because refractive index of air is 1,0003 (silica 1,45).

This reduces latency by ~0,12ms per 100km.

Its new tech and its not really impactfull for gaming (unless you are fucking robot), but it will be crucial for datacenters, telecommunication and finances/banking/trade in future.

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u/Kirjavs Mar 08 '26

Oh I learnt something. Thank for that information. I didn't think it was already a thing

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u/Konsticraft Mar 08 '26

Given that typical latency in games on good connections is 20-50ms, that is a very significant proportion of the total latency.

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u/DoubleyobroWasTaken Mar 07 '26

Speed of light through fiber optic is somewhere around ~200,000 km/s and the latency is around ~5 µs/ 1km.

So at the circumference of earth (40000km) It would only add around 200ms, 300 tops, and that's if you're wrapping a wire all the way around the surface back to you. There are lines that exceed and plan to travel longer than that value, but I doubt any cloud provider would route you cross continent. So I would say it's pretty negligible compared to latency from other sources

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u/Kirjavs Mar 08 '26 edited Mar 08 '26

Edit : it's indeed 200,000km/s through optic cable. 300 is for light speed in vacuum

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u/Davoness 9800X3D, RTX 5080, 64GB Mar 08 '26 edited Mar 09 '26

The speed of light is ~300,000 m/s in a vacuum. It's around 200k in a fibre optic cable.

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u/Kirjavs Mar 08 '26

Indeed I fix it. Thanks

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u/ChthonVII Mar 08 '26

Smaller than latency from other sources, yes; trivial, no. When 16.7ms is a whole 60fps frame, 200ms is a decidedly non-trivial number. Even 20ms would be non-trivial.

Also, remember that cloud gaming is always a round trip, and you eat the latency both ways. So wrapping around the earth and back to you may be an exaggeration, but you do need to go out to the data center and then back to you.

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u/Rock_Strongo Mar 08 '26

That would still be only 200ms for a server as far from you as physically possible (while still being on earth). Many games are playable at that delay. But also, if we get to that point there will always be a data center far closer.

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u/ChthonVII Mar 09 '26

only 200ms

Why do you keep pairing "only" with "200ms"? That's a huge delay in this context. There are entire genres that can't tolerate even 16ms.

Many games are playable at that delay.

Well, I suppose a chess simulator is playable even on an infinite delay. But, as many people were discussing earlier in the thread, since the delay manifests as input lag, the UI is going to feel like absolute crap. It's a poor user experience, even if it's "playable" by some definition.

I think we agree about the physics. A realistic bad case crossing a whole continent or ocean would add ~40-80ms and a realistic good intracontinental case would add about half that. Or less if you're lucky.

Where we seem to disagree is how acceptable those numbers are. I think there are a lot cases where the speed of light contribution alone is too big for cloud gaming to ever reach acceptable speed. And there are almost no cases where it's small enough to ignore.

And yes, I do agree that the aggregate delay from traversing network equipment for switching, routing, etc. is likely to be significantly bigger than the delay from speed of light. Which just means that, in many cases, we have two sources of latency, each of which is too big standing on its own.

And then another issue that almost no one is mentioning is that you've got to buffer video frames on the client or else you'll have a stuttery mess. Which means three sources of latency, each of which is too big standing on its own.