I had a look at the implications of the Facebook Metaverse on emissions from computing. It is scary.

For the ideal VR experience, you need a network bandwidth of 1.6Gbit/s. To watch an HD video at 4K currently, you need 25Mbits/s; 8K would be 100Mbits/s.

So VR requires 64x more bandwidth than 4K video!

Ignoring the infrastructure emissions, purely running this from a cloud data centre effectively means a 64x increase in energy consumption and therefore in carbon emissions.

When I researched my talk about Frugal Computing, I did not discuss VR, as none of the studies I referenced considered it. But with a giant like Facebook behind it, VR might become a very considerable part of our lives.

That would be a disaster: already, emissions from computing are dominated by video. VR will make this many, many times worse.

The only bright side is that with current technologies, there is not enough electricity in the world to power this ideal-experience VR revolution.



@wim_v12e @csepp There's nothing about *federated vrchat* that needs that amount of bandwidth?

I'm guessing they're imagining that they're going to be streaming an entire AAA gameworld every time you walk through a door... I don't think people need or especially want that, and there's a bunch of new compression tech they could adopt if they were serious.

@faun What I describe is what is called the "ideal VR experience" in a technical report from Huawei. All I'm saying is that the bandwidth requirements for this "ideal experience" are entirely unsustainable. This is already taking into account the best possible compression. Otherwise it would be an order of magnitude worse.
For what they call the "fair VR experience" you only need 60Mbit/s, but even that is more than twice that needed for 4K video.

My point about FB is only that if they push it, VR might really take of, whereas previously I didn't think it would.

@csepp

@wim_v12e @csepp The "Cloud VR" report? Wouldn't that be describing the method where it's mostly just streaming video (two eye, 4k, 120fps)?

Hmm Isn't everyone currently making retinal VR screens committed to not doing things that way, including facebook?

I could see it happening later on... But OTOH it represents a tradeoff between having rendering done in the datacenter and having it done on the user's PC/phone, usually the datacenter way, minus transmission costs, would be more efficient?

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@faun I personally think local rendering could be more efficient, esp. if the data centre is far away. The transmission cost is likely to dominate. The worrying part is that these figures (64x in crease in BW) are introduced without any consideration for their impact on emissions. As I've shown, computing emissions are already growing totally unsustainably, and VR will certainly make this worse. And these figures show that it could be *a lot* worse.
I hope it doesn't happen, but hope is not enough.

@csepp

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@wim_v12e
As someone with 0 expertise I'd think actually desirable quality VR will be energy intensive no matter whether rendered locally or centrally. It's either bandwidth way above high quality video or a lot of local graphics processing. Which I doubt will be possible on today's relatively efficient smartphones. Maybe if one is happy with cartoonish graphics. But most likely technical possibilities will be pushed to woo customers, so high energy use. Centralized rendering could be chosen to get everyone in, even with slow/cheap client hardware. But in the end I have no idea. 🤷🏿‍♀️
@faun @csepp

@grob @wim_v12e @faun Centralized rendering has the usual issues of monopolies, plus the added issue of wasteful networking equipment. I really don't think the benefits outweigh the costs.

@csepp @grob FYI, this was a post I made a while ago and had I re-upped it but I have muted the thread.

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