However, it’s clear that this model would lower the burden on Linden Lab’s own servers and thus obviously reduce server-side lag to a degree. That would mostly mean that each resident logged to the sim would probably move around without any lag, while waiting for all the textures to rez properly (which would not depend on LL’s servers any more). I guess that would be an advantage, of course. You’d still need to download individually all those gigabytes of textures — just not from a single server.

BTW,

And where do all the textures come from? You guessed it — from the sim server. Which has to send those 300 MBytes to 100 avatars, or 30 GBytes total. So, on any busy event, we have the poor sim server struggling to push 30 GBytes downstream to all the unhappy and laggy avatars around. There is no way to avoid this step!

Well, there is a way. It would require reworking of the server structure from the scratch but if textures are shared P2P between avatars on the sim, server load would be much lighter. Before IP guardians start screaming at me on the mere metioning that textures are stored locally, they are stored locally already. One can grab them anyway if want to. So it won’t hurt IP rights more then they are in risk now. But it would make the world running much faster.

Good point about in-world chat and old-style attachments with open listeners: these will definitely place a burden on the sim. So a silent audience is a less laggy one The difference might not be huge, but yes, there is still a difference.

You’re also right about the animations, of course. In a 100-person sim, one person sitting down will force everybody else to download about 160 KB (I think that’s the worst-case scenario) for that anim. Add a few more poses and it gets only worse. However, here is the good news: if people are allowed to sit instead of standing, they will just force one download to everybody; while if they’re standing, they will have at least usually 5 poses Also, turning off an AO after teleporting in will do little difference (except for avatars arriving after you): if someone wishes to follow the “attachment nazis” rules, they ought to turn their AO offs before teleporting… or it won’t make any difference whatsoever.

In the year and so since this post, Mono has been introduced, which will run much faster (and lighter on the sim server), even more aggressive culling techniques have been employed, and a lot of improvement has been made in the way prims are fetched from the server, so the “myths” are even more “mythological” than before.

Then again, the point in my article was mostly to explain that there is server-side lag and client-side lag, and that what makes us to suffer most is client-side lag, specially if we cannot do much to reduce it.

Still, these remain true:

- avatars themselves are the major source of lag, even without attachments (both client-side and server-side)
- bad design (ie. too many and too big textures) on the environment are a secondary source of lag, but nevertheless quite an important one (mostly client-side though; the server will only start to get very very laggy if a lot of the environment is constantly moving or is set to physical)
- using badly scripted devices (like, for instance, non-Mono scripts; devices with open listeners; devices with short “polling” cycles, of which the major culprit is sadly the animation overrider, but if you’re sitting down, this shouldn’t make a huge difference; devices with an abuse of sensors like avatar radars; etc.) will cause some overload on the sim servers, but it will bear little influence on client-side lag: turning them off will not decrease client-side lag at all, although it might have a small influence on server-side lag.