It's sad to see that many don't know and don't care for even the basics of reducing lag for themselves and everyone else. They go to huge parties with avatars with a complexity beyond 400,000, with a ZHAO AO, with a radar HUD and with three more HUDs, all with scripts permanently running at full blast, and then they say the sim sucks or the party sucks because the lag is so bad. And it's always someone else's fault.
Of course, if confronted the above, they'll whine that they can't live without any of these HUDs, and they'll accuse me of wanting their avatars to look like 2008 when high heels grew out of the soles of your duck feet.
But let's go through this step by step.
First of all, complexity or ARC (avatar rendering complexity) in short. I guess there aren't exactly few people in OpenSim who don't know what that is or that it even exists, and next to nobody knows their own ARC. But at least Firestorm lets you see the ARC of other avatars as well as your own.
Top menu bar, "Avatar" > "Preferences" > "General" > Check "Show avatar complexity": This will show you the ARC of other avatars.
Top menu bar, "Avatar" > "Preferences" > "General" > Uncheck "Only if too complex" (you have to check "Show avatar complexity" first): This will show everyone's ARC. If you leave it checked, you only see the ARC of "jelly bean" avatars.
Top menu bar, "Avatar" > "Preferences" > "General" > Check "Show own complexity" (you have to check "Show avatar complexity" first): This will show you your own ARC. And I'm pretty sure that many of you will be in for a shock.
Oh, and no, ARC is not a measurement for good looks. You can look good under 50,000, and you can look like crap over 800,000.
Next, radar. You don't need it. No, you don't. Shut up, no, your life doesn't depend on it. It's bad enough if you have the avatar list built into your viewer open all the time. But a scripted radar HUD slows down the grid server, AND it slows down your viewer with its heavy graphics. So either take that thing off or stop whining about the lag.
I seriously wish sim owners could see which avatar wears what kind of script-heavy stuff and face them with the decision of either taking that stuff off or be kicked off the sim and, if they come back with the same crap, banned until the event is over. And I can understand why some party sim owners have decided to disallow avatar scripts on their party sims.
Next, AO. Yes, I know the built-in standard animations are crap. And it's oh soooooo convenient to just go into a freebie store and pick a boxed AO and unpack it and attach it to your avatar. You even get a HUD with it. (By the way, the HUD IS the AO attachment itself. Rez an AO on the ground and see for yourself.)
But in general, AO attachments bring a huge server load with them. That's because they're pretty much always based on a script that's as stolen from SL as the animations themselves. It's called ZHAO, and it's a filthy hack.
What it does is ask the grid server as often as possible whether the avatar has assumed a certain state, i.e. whether the avatar is standing or whether the avatar is sitting or whether the avatar is walking etc. That's over 250 requests per second. Per avatar. As I said, it's a filthy hack, but that's all you can do with Second Life's LSL.
And it's super-convenient for the lazy types who want everything to be as easy and simple as technically possible, and who leave their ZHAO AO switched on even while dancing when the AO can't even do anything.
There are two ways around this. One, as Symphony mentioned, is to put your AO into your viewer. That reduces the grid server load dramatically to almost zero. It isn't too hard to do, there are even several hands-on video tutorials on YouTube (like this one:
https://www.youtube.com/watch?v=PPnJ7bocLY8) which explain how it's done. You'll even have one fewer HUD slowing your viewer down. Seriously, do you actually need that AO HUD? And what for, other than turning the AO off and on again which you can just as well do in the viewer? But I guess it's still too inconvenient in comparison with just putting on a wearable AO.
The other one, if you absolutely insist in just simply putting on your AO as an attachment (because you can't save a viewer AO with an outfit, for example, or because that's just what you do), is named khAOs. It was developed by Kayaker Magic two years ago (
http://magic.kayaker.net/KHAOS/), and it's a replacement script for ZHAO which reduces the server load by some 99% because it does away with all the constant nagging and instead uses special OpenSim features which SL doesn't have.
It's possible to convert existing ZHAO AOs to khAOs, and it isn't even difficult. It's described on Kayaker's website which I've linked to in the above paragraph. It's also described by Kayaker himself in a video (
https://www.youtube.com/watch?v=WNbV-DRld3k). You can get the khAOs script, instructions included, from Kayaker's parcel at OSCC Expo Zone 4 (
https://opensimworld.com/hop/75967); it's to the east where all the surf boards are. And if you don't want to do that, or you think you can't, there are a few places where you can get AOs that have already been converted to khAOs, although I can't guarantee that your favourite AO is among them.
Sadly, I can't see khAOs ever displace ZHAO. For this to happen, the vast majority of freebie stores that offer AOs would have to convert all of them to khAOs or replace them with existing khAOs versions. But as long as nobody knows that khAOs exists or what's so bad about ZHAO, this won't happen.
Finally, what are those other HUDs anyway that people claim they absolutely need even at parties? Facial expressions? As if anyone actually made use of these. And as if anyone actually paid attention to these, at parties with 40 or 50 avatars and 5fps no less. Hand positions? At a party? Makes even less sense for largely the same reasons. Mesh body HUD? Please. Even the HUD that comes with Ruth2 v4 and Roth2 v2 can be taken off once you've got the looks of your avatar under control, and it packs a lot more power than your typical Athena or Adonis HUDs. Dance HUD? Okay, this can be justified. But don't complain about terrible graphics performance while you have about half a dozen dance HUDs open. Special FX HUD? Seriously, whoever has the audacity to fire off whichever kinds of graphics-intense special FX during a party with several dozen avatars should be kicked on the spot.
And if the only reason why you keep all your HUDs on all the time is because you wouldn't find them again in your cluttered inventory if you ever took them off, then you seriously need to learn to organise your inventory. More like a tool box, less like a handbag.